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ImportanceIntraoperative margin assessment is an important technique for ensuring complete tumor resection in malignant cancers. However, in patients undergoing transoral robotic surgery (TORS) for oropharyngeal carcinomas, tissue artifact may provide pathologic uncertainty.ObjectiveTo assess the benefit of providing frozen section control samples (“positive tumor biopsies”) for use during intraoperative margin assessment for patients undergoing TORS for human papillomavirus (HPV)-16–positive oropharyngeal squamous cell carcinoma (OPSCC).Design, Setting, and ParticipantsIn this cohort study, patients receiving curative-intent TORS for biopsy-proven HPV-16–positive OPSCC performed by a single attending surgeon (A.H.M.) at Ronald Reagan UCLA Medical Center from 2017 to 2021 were included in a retrospective data analysis. Exclusion criteria included HPV-negative status, participation in clinical trials, and tumors of unknown primary origin.Main Outcomes and MeasuresSurvival outcomes investigated included overall and disease-free survival. Adverse pathologic outcomes measured included occurrence of nondiagnostic margins and margin reversal from frozen to fixed pathology.ResultsOf the 170 patients included (mean [SD] age, 61.8 [9.9] years; 140 [82%] male), 50% of patients (n = 85) received a frozen section control. Use of a frozen section control was associated with statistically significantly improved sensitivity of intraoperative margin assessment, from 82.8% to 88.9% (difference, 6.1%; 95% CI, 3.9%-8.3%). Eleven percent (n = 18) of all tumors evaluated exhibited at least 1 nondiagnostic intraoperative margin, and 11% (n = 18) experienced margin reversal from frozen to fixed pathology. In patients with nondiagnostic margins, use of frozen section controls was associated with statistically significantly reduced time spent in the operating room (Cohen d, 1.14; 95% CI, 0.12-2.14).Conclusions and RelevanceIn this cohort study, frozen intraoperative margins assessed during TORS resections of HPV-16–positive OPSCC were diagnostically challenging. Adverse pathologic outcomes, such as margin status reversal from positive on frozen pathology to negative on formal analysis, were common. Providing intraoperative frozen section control biopsies may offer clarity in cases with nondiagnostic margins, reducing the need for additional sampling and time spent in the operating room.

Positive pathologic margins following gastric cancer (GC) resection carries a poor prognosis. We evaluated intraoperative frozen section (IFS) analysis of resection margins (RMs) as a quality indicator in GC surgery.Patients referred to a provincial cancer agency with surgically resected non-metastatic GC between 2004 and 2012 were included. Associations between IFS analysis, other baseline characteristics, RMs, and overall survival (OS) were assessed using logistic regression, Kaplan-Meier analyses, and Cox proportional hazards modeling.Among 377 patients, median age was 67 years, 68% were male, and 16% had +RMs. Thirty-four percent of patients underwent IFS analysis, which protected against +RMs (odds ratio [OR]: 0.34, 95% confidence interval [CI]: 0.16-0.73, p = 0.006) and improved OS (hazards ratio [HR]: 0.72, 95% CI: 0.54-0.98, p = 0.037). OS following re-resection of IFS positive patients was similar to IFS negative patients (69 vs. 54 months, p = 0.317). Stage III disease (OR: 12.8, 95% CI: 3.00-55.0, p = 0.001) and gastroesophageal junction tumors (OR: 2.25, 95% CI: 1.05-4.78, p = 0.036) predicted +RMs. Stage III disease led to worse OS (HR: 2.89, 95% CI: 1.92-4.34, p 0.001) while intestinal histology improved OS (HR: 0.67, 95% CI: 0.50-0.90, p = 0.007).IFS analysis reduce +RMs and improve OS and should be incorporated in curative intent GC surgery for patients with locally advanced GC.

In adult women, most malignant ovarian tumors are epithelial in origin. The use of intra-operative frozen section to distinguish between benign and malignant histology is reliable in guiding operative decision-making to determine the extent of surgical staging required. Pediatric and adolescent patients with ovarian masses have a much different spectrum of pathology with most tumors arising from germ cell precursors. This review was undertaken to assess the concordance between the intra-operative frozen section and the final diagnosis as an aid to guide extent of surgical staging in a group of pediatric and adolescent patients with malignant ovarian germ cell tumors.Records of patients aged 0 to 20 years with malignant ovarian germ cell tumors enrolled on Children's Oncology Group study AGCT0132 were reviewed. Pathology reports from patients who had both intra-operative frozen section diagnosis and final paraffin section diagnosis were compared using descriptive statistics. By inclusion criteria for the study, all patients had a final diagnosis of malignancy with required yolk sac tumor, choriocarcinoma or embryonal carcinoma histology. Available central review of pathology final paraffin section slides were compared with final institution pathology reports.Of 131 eligible patients with ovarian germ cell tumors, 60 (45.8%) had both intra-operative frozen section and final paraffin section diagnoses available. Intra-operative frozen section diagnoses were classified as: incorrect diagnosis of benign tumor (13.3%), confirmation of malignancy (61.7%), immature teratoma (16.7%), germ cell tumor not otherwise specified (5%) and no diagnosis provided (3.3%). Intra-operative frozen section was incorrect in 23 of 60 (38.3%) patients evaluated. Central pathology review was concordant with the final institution pathology diagnosis in 76.3% of patients. Central pathology review identified additional germ cell tumor components in 23.7% of patients.In pediatric and adolescent patients with a confirmed final diagnosis of ovarian germ cell malignancy, intra-operative frozen section diagnosis is not reliable to inform the extent of surgical staging required. Central review by an expert germ cell tumor pathologist provides important additional information to guide therapy.

Margin status is one of the most important prognostic factors in oral cancers. Intraoperative frozen section (FS) can be performed to ensure a margin-negative resection, however the method of FS assessment is debatable. The aim of this study was to compare the defect-driven (DDA) versus specimen-driven (SDA) approach for intraoperative assessment of tumour margins in oral cancer resections and their impact on loco-regional recurrence and survival. The primary study endpoint was margin status determined from the final histopathological examination report. Secondary endpoints were disease recurrence and survival. This retrospective cohort study compared the two methods of FS in terms of their performance and survival outcomes. All oral squamous cell carcinoma patients who underwent surgery as the primary treatment from January 2018 to February 2019 were included. The involved margin rate was slightly lower with SDA than DDA (7.5% vs 11.8%), however the difference was not statistically significant. The recurrence rate was higher with DDA (19/51, 37.2%) than SDA (14/53, 26.4%), although this was not statistically significant. Local recurrence-free survival (DDA 62% vs SDA 75%; P = 0.653) and overall survival (DDA 76% vs SDA 78%; P = 0.300) at 18 months of follow-up were comparable. There was no significant difference in sensitivity or specificity of intraoperative FS for margin assessment between SDA and DDA. The type of intraoperative FS technique used did not affect loco-regional recurrence or overall survival.

Although its clinical effect is reported to last up to 2 years, how long hyaluronic acid filler (HAF) histologically persists in the skin is unknown.To determine the approximate persistence time of HAF in the skin and to correlate persistence time with HAF histological appearance, size, depth, and location.Retrospective review of patient data and available frozen sections from 2003 to 2021 in which HAF was identified in 36 Mohs micrographic surgery patients.Incidental HAF histologically persisted in the skin for as long as 10.75 years in 1 patient and 3 years or more in 36.8% (7/19) of the patients who remembered the time of implantation. HAF is more apparent in frozen sections stained with toluidine blue than those stained with hematoxylin and eosin. Although HAF volume tended to be less with time, fragmentation was present both early at 3 months and at 3 years or more. There was no correlation of persistence time with anatomic location or depth. In 90.3% of the cases (28/31), HAF was located in the subcutaneous fat. There was no granulomatous or giant cell response at any time period.Hyaluronic acid filler may be seen histopathologically in the skin, usually in the subcutaneous fat, up to 10.75 years after implantation.

Purpose of review The aim of this review is to discuss recent studies on the assessment of tumor extension and resection margins by different intraoperative techniques allowing for image-guided surgery of oral cancer. Recent findings There are different in-vivo and ex-vivo intraoperative techniques to improve margin control of which intraoperative ultrasound and targeted fluorescence-guided resections have high potential clinical value and are closest to clinical implementation. In oral cancer surgery, resection margins, particularly deep margins, are often inadequate. Intraoperative frozen section does not improve resection margin control sufficiently. Specimen-driven intraoperative assessment for gross analysis of suspected margins reduces the amount of positive resection margins substantially but leaves still room for improvement. Mucosal staining methods, optical coherence tomography and narrow band imaging can only be used for superficial (mucosal) resection margin control. Spectroscopy is under investigation, but clinical data are scarce. Intraoperative ex-vivo imaging of the resection specimen by magnetic resonance and PET/computed tomography may be used to assess resection margins but needs more research. Intraoperative in-vivo ad ex-vivo ultrasound and targeted fluorescence imaging have high potential clinical value to guide oral cancer resections and are closest to clinical implementation for improved margin control.

Spread through air spaces (STAS) is reportedly associated with worse prognosis in sublobar resections of lung adenocarcinoma. Recently, it was proposed that STAS detected on frozen sections can be an indication for lobectomy instead of sublobar resection. We undertook this study to evaluate the reliability of STAS assessment on frozen sections compared to permanent sections, as well as the associations among STAS, tumor grade, and recurrence-free survival (RFS) after sublobar resection. A total of 163 stage I lung adenocarcinoma resections with frozen sections were identified retrospectively. For each case, and for frozen and permanent sections separately, the presence or absence of STAS, as well as the tumor grade, were recorded. Compared to permanent sections, STAS detection on frozen sections had low sensitivity (55%), low positive predictive value (48%), and fair agreement (K = 0.34), whereas there was higher specificity (80%) and negative predictive value (85%). Accuracy was 74%. Tumor grade assessment on frozen sections showed higher sensitivity (77%), positive predictive value (90%), agreement (K = 0.72), specificity (94%), and accuracy (87%), and the same negative predictive value (85%). High-grade histology on frozen sections was associated with shorter RFS (p = 0.02), whereas STAS on frozen sections was not (p = 0.47). Our results suggest that the intraoperative detection of STAS has low sensitivity and positive predictive value. False-positive results may lead to overtreatment of patients with lung cancer. The determination of tumor grade on frozen sections offers better sensitivity and specificity, plus it is associated with RFS, whereas STAS on frozen sections is not. Further study is needed to explore the utility of assessing tumor grade on frozen sections.

Objectives: To measure the diagnostic accuracy of intraoperative frozen section examination of sentinel lymph nodes (SLN) in vulvar cancer and to describe associated patient outcomes. Methods: This retrospective cohort study included patients with invasive squamous cell carcinoma of the vulva who underwent SLN biopsy with intraoperative frozen section at one cancer centre from Jan 2008 - Feb 2020. Exclusion criteria were tumor size >4cm, multifocal tumor, palpable groin lymph nodes and neoadjuvant therapy. The SLN procedure was performed by injection of the primary vulvar tumor or scar with technetium-99m, ICG and/or blue dye. We compared the intraoperative SLN frozen section diagnosis and the paraffin section report for concordance. Recurrence location was described and recurrence free survival (RFS) was compared using the Kaplan-Meier method. Results: A total of 173 patients (258 groins) met inclusion and exclusion criteria. On frozen section, there were 36/258 positive groins on frozen section and 222 negative groins. On final pathology, there were 39/258 positive groin nodes: 30 macro-metastases, 7 micro-metastases, 2 isolated tumor cells (ITCs). There were 219 negative groins. The sensitivity and specificity for frozen section detecting any metastatic disease compared to final pathology, was 89.7% and 99.5%, respectively. The positive-predictive value (PPV) was 97.2% and the negative-predictive-value (NPV) was 98.2%. There were 4 cases of false negative frozen section where final pathology revealed two cases of ITCs, 1 micro-metastasis and 1 macro-metastasis. A total of 30 patients (17.3%) underwent a full inguinal femoral lymphadenectomy during the same operation due to the frozen section results and avoided a second operation. A total of 2 patients (1.2%) required a second operation for lymphadenectomy due to false negative results on frozen section. Median (range) follow up was 38.0 (1-137.8) months. Median RFS was 14.9 (3.6 to 98.2) months. There were 46 recurrences in the study population, of which 29 were confined to the vulva, 9 groin recurrences and 8 distant recurrences. Among patients with a negative SLN biopsy on both frozen section and final pathology, there were 10 (3.9 %) groin and/or distant recurrences. A total of 6 nodal recurrences were ipsilateral, 1 was contralateral, 2 were bilateral and 1 recurrence was distant. After exclusion of patients with local recurrence only, the RFS at 3 years was 91.6% (95% CI 86.2-97.4%) for patients with negative SLN on frozen section and 64.6% (95% CI 46.5-89.7%) for positive SLN on frozen section. On final pathology, patients with negative SLN had a 3-year RFS of 91.7% (95% CI 86.3-97.4%), macro-metastases 58.4% (95% CI 38.5-87.7%), and micro-metastases/ITCs was 100%. Conclusions: Intraoperative frozen section of SLNs in vulvar cancer is an accurate intraoperative guide to determine if complete inguinal femoral lymphadenectomy should be performed. SLN biopsy reduced the need for a second surgical procedure and does not appear to compromise patient outcomes.

The utility of frozen section evaluation of the pancreatic parenchymal resection margin(s) in the surgical management of intraductal papillary mucinous neoplasm (IPMN) remains controversial. We investigated the frequency of its use in IPMN resections and its impact on achievement of negative final parenchymal margin(s).Sixty-two IPMN resections (11 with invasive carcinoma) performed over a 12-year period were studied.Frozen sections of the parenchymal margin(s) were performed on 44 of the 62 resections (71%), 30 (68%) of which had 10 positive and 22 indefinite margins on frozen section. Additional margin resections were performed in 14 of these 30 cases (47%), boosting the complete resection rate from 14% (2 of 14) on the initial margin(s) to 71% (10 of 14) on the final margin(s) (P = 0.002). Overall, negative final parenchymal margin(s) were achieved more frequently when evaluation of the initial margin(s) by frozen section was performed (35 of 44; 80%) than when it was not (11 of 18; 61%) (P = 0.13).In the intraoperative management of IPMN, frozen sections are highly reliable for margin evaluation and are useful for guiding the extent of pancreatic resection.

Purpose: A primary medical relevance of thyroid nodules consists of excluding thyroid cancer, present in approximately 5% of all thyroid nodules. Fine-needle aspiration biopsy (FNAB) has a paramount role in distinguishing benign from malignant thyroid nodules due to its availability and diagnostic performance. Nevertheless, intraoperative frozen section (iFS) is still advocated as a valuable tool for surgery planning, especially for indeterminate nodules. Methods: To compare the FNAB and iFS performances in thyroid cancer diagnosis among nodules in Bethesda Categories (BC) I to VI. The performance of FNAB and iFS tests were calculated using final histopathology results as the gold standard.Results: In total, 316 patients were included in the analysis. Both FNAB and iFS data were available for 272 patients (86.1%). The overall malignancy rate was 30.4%% (n=96). The FNAB sensitivity, specificity, and accuracy for benign (BC II) and malignant (BC V and VI) were 89.5%, 97.1%, and 94.1%, respectively. For all nodules evaluated, the iFS sensitivity, specificity, and accuracy were 80.9%, 100%, and 94.9%, respectively. For indeterminate nodules and follicular lesions (BC III and IV), the iFS sensitivity, specificity, and accuracy were 25%, 100%, and 88.7%, respectively. For BC I nodules, iFS had 95.2% of accuracy.Conclusion: Our results do not support routine iFS for indeterminate nodules or follicular neoplasms (BC III and IV) due to its low sensitivity. In these categories, iFS is not sufficiently accurate to guide the intraoperative management of thyroidectomies. iFS for BC I nodules could be a reasonable option and should be specifically investigated.

Introduction: Upper tract urinary cancer recurrence (UTUCR) after radical cystectomy (RC) is outcome-limiting. Surgical recommendations on intraoperative performance of frozen section analysis (FSA) and management of positive ureteral margin (PUM) are lacking. Methods: 634 RC cases were identified (2010–2018). In patients with PUM, sequential ureteral resections up to a negative margin were performed. We investigated the accuracy of FSA, significance of PUM, and identified risk factors (RFs) to stratify patients for UTUCR. Results: FSA was performed in 355 patients, including a total of 693 ureters. FSA sensitivity was 0.93 and specificity 0.99. PUM conversion was possible in 52 (91.2%) cases. UTUCR occurred in 17 (4.8%) patients. Identified UTUCR RFs are non-muscle invasive bladder carcinoma (NMIBC) (OR 3.8, 95% confidence intervals [CI] 1.4–10.2, p = 0.008), multifocal bladder cancer in cystectomy specimen (OR 4.7, CI 1.1–20.8, p = 0.042), and recurrent NMIBC (OR 4.1, CI 1.5–10.9, p = 0.006). Risk-group stratification showed a six-fold increase in UTUCR risk (low-to high-risk). Conclusion: FSA is a sensitive and specific method to identify PUM. UTUCR occurs significantly more often in patients with recurrent, multifocal NMIBC at the time of RC. Patients can be risk stratified for UTUCR. In case of NMIBC-PUM, surgeons can safely opt for a kidney preserving strategy.

Approximately 6% of deceased kidney donors (DKDs) are diabetic; their kidneys may be associated with worse allograft survival, but published studies suggest that recipient diabetes status has a greater impact on mortality and survival. Since biopsy findings are the most common reason for organ discard, we sought to understand histologic and clinical factors that influence graft survival in patients who receive a kidney from a diabetic DKD. We retrospectively reviewed our institutional experience from 2005 to 2019, and re-evaluated pre-implantation and earliest post-transplant biopsies. Histologic findings were compared against a control cohort of non-diabetic DKD. Of 829 adult DKD transplants, 37 (4.5%) came from diabetic donors. There was no significant difference in diabetic vs. non-diabetic DKD graft survival for all-comers; however, when stratified by duration of donor diabetes, donor diabetes ≥6 years was associated with graft failure. In 25 patients with post-transplant biopsies available, diabetic DKD allografts had significantly greater non-glomerular chronic injury than non-diabetic DKD allografts. Moderate arteriolar hyalinosis (in 24%), moderate tubular atrophy and interstitial fibrosis (IFTA, in 36%), and diabetic glomerulopathy (in 24%) on early post-transplant biopsy were associated with allograft failure. Pre-implantation frozen section discrepancies were more common in long-standing donor diabetes, and arteriolar hyalinosis and IFTA scores on frozen accurately prognosticated graft loss. There was no morphologic improvement in lesions of diabetic nephropathy on short-term follow-up. In conclusion, donor diabetes ≥6 years, and histologic findings on frozen section and early post-transplant biopsy are associated with diabetic DKD allograft loss.

Central nervous system (CNS) tumors are now the most common type of solid tumor in individuals aged 0–19 years, with an incidence rate in the United States around 5 per 100,000, accounting for about 1 out of 4 childhood cancers. Pediatric pathologists encounter brain tumor cases with varying frequency, but many of these encounters begin in the context of intraoperative consultation or “frozen section.” This review provides an overview of the technical aspects of intraoperative consultation specific to, or more helpful in, CNS tumors, emphasizing helpful cytologic and histologic features of the more commonly encountered pediatric CNS tumors, and illustrating some common diagnostic pitfalls and how these may be avoided.

Background Mohs micrographic surgery (MMS) has risen in popularity as a management option for treating lentigo maligna (LM) because of its ability to accurately detect subclinical spread while conserving tissue. The primary concern for opponents of MMS in melanoma remains the difficulty associated with interpretation of frozen sections compared with traditional paraffin sections; this has been made easier with the advent of immunostaining. Objective Our study aims to assess the concordance in clearance reporting of LM in immunostained frozen sections compared with permanent paraffin sections and hematoxylin and eosin staining. Methods We conducted a retrospective analysis of 38 LM cases treated by MMS between 2017 and 2020 in Melbourne, Australia. Immunostained frozen sections were assessed by a Mohs surgeon, whereas permanent paraffin sections were assessed by an external dermatopathologist. Results We report 86% agreement in reporting of LM in immunostained frozen sections compared with permanent paraffin sections. In 5/38 cases, permanent paraffin sections were reported as clear for LM, but the Mohs surgeon had detected positive margins, requiring further excision. Conclusion For LM treated with MMS, there is a high agreement of clearance reporting between immunostained stained frozen sections and permanent paraffin sections without immunostaining; however, immunostained frozen sections may be more sensitive.

Background Surgeons sometimes have difficulty determining which result to favor when preoperative results (MRI + preoperative endometrial biopsy [pre-op EB]) differ from intraoperative frozen section histology (FS) results. Investigation of how FS can complement ordinary preoperative examinations like MRI and pre-op EB in identification of patients at high risk of lymph node metastasis (high-risk patients) could provide clarity on this issue. Therefore, the aim of this study is to assess the utility of pre-op EB, MRI and FS results and determine how to combine these results in identification of high-risk patients. Methods The subjects were 172 patients with endometrial cancer. Patients with a histological high-grade tumor (HGT), namely, grade 3 endometrioid cancer, clear cell carcinoma or serous cell carcinoma, or with any type of cancer invading at least half of the uterine myometrium were considered high-risk. Tumors invading at least half of the uterine myometrium were classified as high-stage tumors (HST). We compared (a) detection of HGT using pre-op EB versus FS, (b) detection of HST using MRI versus FS, and (c) identification of high-risk patients using MRI + pre-op EB versus FS. Lastly, we determined to what degree addition of FS results improves identification of high-risk patients by routine MRI + pre-op EB. Results (a) Sensitivity, specificity, and accuracy for detecting HGT were 59.6, 98.4 and 87.8% for pre-op EB versus 55.3, 99.2 and 87.2% for FS (P = 0.44). (b) These figures for detecting HST were 74.4, 83.0 and 80.8% for MRI versus 46.5, 99.2 and 86.0% for FS (P < 0.001). (c) These figures for identifying high-risk patients were 78.3, 85.4 and 82.6% for MRI + pre-op EB versus 55.1, 99.0 and 81.2% for FS (P < 0.001). The high specificity of FS improved the sensitivity of MRI + pre-op EB from 78.3 to 81.2%, but this difference was not statistically significant (P < 0.16). Conclusion Frozen section enables identification of high-risk patients with nearly 100% specificity. This advantage can be used to improve sensitivity for identification of high-risk patients by routine MRI + pre-op EB, although this improvement is not statistically significant.

Preoperative diagnosis for suspected gallbladder cancers is challenging, with a risk of overtreating benign disease, for example, xanthogranulomatous cholecystitis, with radical cholecystectomies. We retrospectively evaluated the surgeon's intraoperative assessment alone, and with the addition of intraoperative frozen sections, for suspected gallbladder cancers from a tertiary hepatobiliary multidisciplinary team (MDT).MDT patients with complex gallbladder disease were included. Collated data included demographics, MDT discussion, operative details, and patient outcomes.A total of 454 patients with complex gallbladder disease were reviewed, 48 (10.6%) were offered radical surgery for suspected cancer. Twenty-five underwent frozen section that led to radical surgery in 6 (25%). All frozen sections were congruent with final histopathology but doubled the operating time (p 0.0001). Both the surgeon's subjective and additional frozen section's objective assessment, allowed for de-escalation of unnecessary radical surgery, comparing favourably to a 13.0% cancer diagnosis among radical surgery historically.The MDT process was highly sensitive in identifying gallbladder cancers but lacked specificity. The surgeon's intraoperative assessment is paramount in suspected cancers, and deescalated unnecessary radical surgery. Intraoperative frozen section was a safe and viable adjunct at a cost of resources and operative time.

Tailoring axillary surgery to disease burden has occurred for patients treated with breast-conserving surgery, but limited data exist for patients treated with mastectomy, thus most of these patients who are clinically node-negative but found to be pathologically node-positive are treated with axillary dissection. From 2295 clinically node-negative mastectomy patients treated at our institution 2008-2018, we studied 338 with 1-2 positive sentinel nodes. Patients with a positive sentinel node identified on intraoperative frozen section pathology had a higher nodal disease burden. 66 of 108 patients (61%) whose nodal disease was identified only on permanent section pathology were treated with sentinel node surgery without axillary dissection with no 5-year regional nodal recurrences. This approach permits tailoring axillary surgery in most clinically node-negative mastectomy patients whilst avoiding a second operation. Introduction : Controversy exists regarding optimal management of the axilla in clinically node-negative (cN0) mastectomy patients with 1-2 positive sentinel nodes (+SLNs). We evaluated the influence of frozen section pathology on axillary management and recurrence. Materials and Methods : We studied cN0 breast cancer patients treated 2008-2018 with mastectomy and SLN surgery with 1-2+SLNs. Patients with 1-2+SLNs identified on frozen section intraoperatively (FS+SLN) were compared to those with 1-2+SLNs not detected by frozen section (FS–SLN). Recurrence rates were estimated using the Kaplan-Meier method. Results : Of 2295 cN0 mastectomy patients, 338 had 1-2+SLNs: 108 (32%) FS-SLN and 230 (68%) FS+SLN. In FS+SLN cases, completion axillary dissection (cALND) was more frequent (97% versus 39%, p Conclusions : Mastectomy patients with 1-2 FS+SLNs have a higher nodal disease burden than FS-SLN patients. The majority of FS+SLN patients underwent cALND and 52% received PMRT with very low 5-year regional nodal recurrence rates. A substantial proportion of FS-SLN patients successfully avoided both cALND and PMRT. Frozen section pathology analysis can guide de-escalation of axillary management.

To assess accuracy of whole slide imaging (WSI) in the interpretation of permanent and frozen sections in surgical pathology and the identification of tumors in cutaneous en face frozen sections.Twenty glass slides containing cutaneousPercent agreement between LM and WSI was 100%, with Cohen's kappa of 1.0. The average time taken to determine tumor presence was significantly greater using WSI than LM. Similarly, the surgeon was significantly more confident using LM than WSI.This proof-of-concept study suggests that diagnostic concordance is excellent between LM and WSI in the evaluation of Mohs frozen sections. However, WSI was cumbersome to use, not ergonomic, and required significantly more time.

Histological examination during surgery (FS) has a place in the surgical management of differentiated thyroid carcinoma (DTC). Extending the indication for limited surgery to 4 cm tumor size (ATA guidelines 2015) cytologically verified DTCs, increases the emphasis on accurate patient selection. In our work, we reflected on the effectiveness of FS and its relationship to optimal patient management.In a single-center retrospective study, we evaluated the documentation of patients indicated for primary surgery for DTC from January 1, 2016 to December 31, 2020 - there was 489 patients collectively, 121 were men, median age was 50 years (1681), 73 patients (female, age 1845 years) with preoperatively identified low-risk DTC (size 1140mm) were indicated for lobectomy.34 patients (46.6%) did not meet the criteria for limited surgery 15 patients were identified from FS of the lymph nodes of the central compartment (LNCK) (15 of 25 patients) - 1 patient with false negative result and 6 patients with FS of the thyroid gland (SH) (6 / 41) - 11 patients with false negative findings. Two-step OP surgery was performed on 13 patients (17.8%). FS of LNCK identified high-risk cancer and reduced the risk of two-step surgery compared to the group of patients in whom FS was not performed or was performed from thyroid gland. The difference was statistically significant (OR 1.93, p=0.026).Approximately ½ of the patients from preoperatively identified low-risk cancers in our cohort met the criteria for limited surgery. About 30% of them eventually needed a two-step operation. Perioperative examination of LNCK helps to perform radical surgery at one time.

Frozen Sections (FS) are used to assess margins, for staging, and primary diagnosis. FS guide intraoperative treatment decisions in oncological gastro-intestinal tract surgeries and further management of the patients.To analyze the distribution, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of frozen sections in gastrointestinal pathology in our institution during the period of 3 years (2016-2018).This study was an audit to determine the accuracy of FS reports by comparing them with the paraffin section (PS) reports. The FS diagnoses and their PS diagnoses were noted in 1704 gastrointestinal surgeries during the period from 2016 to 2018. Discrepancies were noted and slides of discrepant cases were reviewed to determine the cause. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated using the standard formulae.Out of 1704 cases, correct diagnosis on frozen section was made in 1649 cases (96.77%), 20 (1.17%) were deferred cases, and 35 (2.05%) were discrepant cases. The commonest discrepancies were seen in the primary diagnosis of the gall bladder and gastrectomy margins. The commonest causes for discrepancies were interpretation errors and technical errors. Sensitivity was 91.71%, specificity was 99.69%, positive predictive value was 98.84%, negative predictive value was 97.68%, and accuracy was 97.92%.FS diagnosis is a reliable guide to surgeons for intraoperative management. Studying deep cuts and careful sampling at frozen sections will help reduce discrepancies.

Background: Basal cell and squamous cell carcinomas (BCC and SCC) are the most common types of cancer worldwide. Intraoperative assessment of surgical margins by frozen section has been widely used to ensure disease-free margins. The intraoperative ‟en face” freezing technique evaluates all peripheral and deep margins. Objective: To report the results of the ‟en face” freezing technique in relation to tumor recurrence and agreement with paraffin-embedded tissue examination. Methods: Retrospective analysis of patients undergoing surgical excision of BCC and SCC at the A. C. Camargo Cancer Center, Brazil. Results: This study included 542 skin carcinomas, which were excised from 397 patients. A total of 201 male patients (50.6%), and 196 female patients (49.4%) were assessed, whose mean age was 64 years. The tumors were mostly located on the head and neck region (87.8%). BCC corresponded to 79.7% of the cases. The mean follow-up was 38 months. Tumor relapse occurred in 0.86% of the primary tumors and 3.7% of recurrent tumors. The result of the intraoperative ‟en face” frozen section evaluation was in agreement with the final result of the anatomopathological examination (paraffin test) in 98% of the lesions. Study limitations: Not having a minimum follow-up time of 5 years for all patients. Conclusion: The ‟en face” freezing technique shows low tumor relapse, being reliable and safe to guarantee negative surgical margins of the tumor.

Objectives: The widespread use of ultrasonography for the investigation of common urological conditions, such as infertility or pain, has resulted in an increased incidence of incidental non-palpable testicular masses. The majority of these are expected to be benign therefore a conservative approach, either active monitoring or organsparing approach, is recommended. However, there are no clinical or radiological parameters which define the exact nature of such lesions and optimal patient selection criteria are lacking. In this comprehensive review we discuss the significance of incidental, small testicular masses (STMs) and the role of organ-sparing approach in the management of these lesions. Materials and methods: A non-systematic search was performed using PubMed to identify articles that covered the following topics; clinical implications at diagnosis, role of imaging in identifying the malignant capabilities of a lesion, role of surgery and the final pathology. Results: Incidental STMs are routinely identified following ultrasound examination of infertile men. STMs usually measure a few millimeters in size and the majority of these are benign. Therefore, strict follow up or an organ-sparing approach, with utilisation of frozen section analysis (FSA), is favored for STMs. FSA has a high correlation with final pathology and prevents unnecessary orchidectomies. Advances in imaging, namely ultrasound and magnetic resonance imaging may provide enhanced assessment of STMs and guidance intraoperatively. Conclusions: The optimal approach is not well defined and there is no specific clinical parameter that can predict the nature of STMs. The increasing incidence of small, benign testicular masses has resulted in the development of organ-sparing surgery to investigate and manage these lesions. Organ-sparing surgery has been shown to be practical and carries excellent oncological outcomes.

Background At present, lobectomy is still the standard treatment for lung cancer. Judging whether a lesion is invasive adenocarcinoma (IA) has important guiding significance for determining the scope of surgical resection. The commonly used methods are intraoperative frozen sections and computed tomography (CT) signs. There is still controversy about the accuracy of both in judging the invasiveness of ground‐glass nodules (GGNs). Methods The clinical data of patients with GGNs who underwent surgery were collected. According to the results of univariate analysis, the variables with statistical differences were selected and included in logistic regression multivariate analysis. The predictive variables were determined and the receiver operating characteristic (ROC) curve was drawn in order to achieve the area under the curve (AUC) value. Results According to the results of logistic regression analysis, the longest diameter and maximum CT value of nodules were independent risk factors for IA. The mathematical prediction model of CT signs was determined, and the ROC curves of CT signs and intraoperative frozen sections (FS) were drawn, respectively. The AUC values under the curves were calculated to be 0.873 and 0.807, respectively. The mathematical prediction model of intraoperative frozen section combined with CT signs was established. A ROC curve was drawn and the AUC was calculated to be 0.925. Conclusions The diagnostic accuracy of CT signs in judging whether nonbenign GGNs were IA was higher than that of intraoperative FS. Combined with CT signs and intraoperative FS to establish a mathematical prediction model, the diagnostic accuracy of judging whether nonbenign GGNs are IA is significantly improved., The receiver operating characteristic (ROC) curves for the mathematical prediction model (not included in the intraoperative frozen section). The area under the curve (AUC) value using the prediction model was 0.873.

Background Frozen section (FS) pathology has multiple limitations, and different institutions report variable experiences with the use of FS for diagnosis of tumor involvement. We aimed to compare the FS accuracy with that of permanent pathology (gold standard) regarding marginal involvement and lymph node status using data from the largest breast cancer registry in Iran. Methods In this retrospective study, women who had both FS and permanent pathology reports were included. The two pathology reports were cross compared with regard to the involvement of tumor margins and sentinel lymph nodes. Results Overall, 2786 patients entered the study. Mean age of patients was 48.96±11.44 years. A total of 1742 margins were analyzed. Accordingly, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FS pathology for detection of involvement of involved margins were 78.49%, 97.63%, 65.1%, and 98.7%, respectively. The accuracy and area under the curve (AUC) for FS pathology were 96.61% and 0.73 (95% CI: 0.64–0.831), respectively. A total of 1702 sentinel lymph node biopsies were assessed. Sensitivity, specificity, PPV, and NPV, of FS pathology for detection of lymph node involvement, were 87.1%, 98%, 95.5%, and 93.3%, respectively. Accuracy and AUC of FS for diagnosis of involved lymph nodes were 94.1% and 0.926 (95% CI: 0.909–0.942), respectively. Conclusion Frozen pathology is a suitable method for identifying involved sentinel lymph nodes in patients with breast cancer, but this method has a less than optimum efficacy for detecting and confirming marginal involvement.

Ovarian cancer is the seventh most common form of cancer among women worldwide. The aim of the study was to determine the accuracy of a frozen section and the factors affecting the accuracy of frozen diagnosis of ovarian neoplasms. This retrospective, cross-sectional study was conducted on 401 patients with ovarian masses with frozen section diagnosis in Shahid Faghihi Hospital affiliated to Shiraz University of Medical Sciences between 2014 and 2018. Each ovarian tumor sample was evaluated for histopathologic diagnosis using frozen and paraffin-embedded sections, which were reviewed by an expert gynecologic pathologist. Accuracy and diagnostic values were estimated by comparing the results of the 2 techniques, using the paraffin section as the gold standard. The overall accuracy of the frozen section was 94.5%. Its sensitivity was 85.3% for malignant, 88.2% for borderline, and 99.6% for benign tumors. Its specificity was also 99.7% for malignant, 98.0% for borderline, and 90.9% for benign tumors. The positive predictive value was 98.9% for malignant, 86.5% for borderline, and 94.6% for benign tumors. Most false negatives occurred in mucinous and borderline tumors. The sensitivity of malignant tumors of germ cell and sex cord-stromal cell types were 64.3% and 95.5%, respectively. The specificity of germ cell and sex-cord stromal tumors were 100% and 93.8%, respectively. Frozen section seems to be a precise technique for histopathologic diagnosis of ovarian tumors. However, borderline and mucinous tumors are the most problematic issues during frozen section diagnosis and malignant germ cell tumors have the lowest sensitivity.

Although there have been several reports of the diagnostic accuracy of frozen section biopsy (FSB) for parotid gland tumors, few studies have focused on its diagnostic accuracy for submandibular gland tumors.This study aimed to investigate the necessity of FSB with regard to its diagnostic accuracy for submandibular gland tumors (SGTs).About 42 SGT patients underwent both fine-needle aspiration cytology (FNAC) and FSB between 2005 and 2020. The results of FNAC and FSB were analyzed and compared with the final histological diagnoses.The respective sensitivity and specificity in detecting malignant tumors in 38 cases, excluding the four indeterminate FNAC cases, they were 0 and 97% for FNAC, and 100 and 97% for FSB. Considering the four indeterminate FNAC cases to be malignant, the respective sensitivity and specificity in detecting malignant tumors in the 42 cases were 50 and 92% for FNAC, and 100 and 95% for FSB.FSB may be useful for malignancy detection as a final histological diagnosis in cases that are diagnosed as benign or indeterminate by FNAC in SGTs.

Homozygous deletion of methylthioadenosine phosphorylase (MTAP) in cancers such as glioblastoma represents a potentially targetable vulnerability. Homozygous MTAP-deleted cell lines in culture show elevation of MTAP’s substrate metabolite, methylthioadenosine (MTA). High levels of MTA inhibit protein arginine methyltransferase 5 (PRMT5), which sensitizes MTAP-deleted cells to PRMT5 and methionine adenosyltransferase 2A (MAT2A) inhibition. While this concept has been extensively corroborated in vitro, the clinical relevance relies on exhibiting significant MTA accumulation in human glioblastoma. In this work, using comprehensive metabolomic profiling, we show that MTA secreted by MTAP-deleted cells in vitro results in high levels of extracellular MTA. We further demonstrate that homozygous MTAP-deleted primary glioblastoma tumors do not significantly accumulate MTA in vivo due to metabolism of MTA by MTAP-expressing stroma. These findings highlight metabolic discrepancies between in vitro models and primary human tumors that must be considered when developing strategies for precision therapies targeting glioblastoma with homozygous MTAP deletion., The metabolite methylthioadenosine (MTA) inhibits PRMT5. Therefore, MTA accumulation due to MTA phosphorylase (MTAP) deletion has been proposed as a vulnerability for PRMT5-targeted therapy in cancer. Here, the authors show that MTA does not accumulate in MTAP-deficient cancer cells but is secreted and metabolized by MTAP-intact cells in the tumour microenvironment.

Evaluation of axillary lymph nodes after sentinel lymph node biopsy (SLNB) in breast cancer is mostly done by intra-operative frozen section biopsy (FSB) and/ or touch imprint cytology (TIC). In this systematic review and meta-analysis, we have compared the accuracy of the two modalities.PubMed, EMBASE, and Cochrane electronic databases were searched for articles comparing TIC with FSB. Articles were assessed for methodological and reporting quality. The main summary measures were pooled sensitivity, pooled specificity, and diagnostic accuracy using bivariate generalized linear mixed models using random effects.Fourteen studies were included. The pooled sensitivity, specificity, and diagnostic accuracy for FSB were 78%, 100%, and 98.57%. For TIC, the pooled sensitivity, specificity, and diagnostic accuracy were 74%, 98%, and 98.37%. For both methods, visual inspection of summary ROC curves and of forest plots did not show significant heterogeneity.TIC showed comparable sensitivity, specificity, and accuracy to FSB and hence can be used as its substitute as a rapid and economical test for the detection of axillary lymph node metastasis during SLNB especially in low-resource settings.

Intraoperative frozen-section analysis provides real-time margin resection status that can guide intraoperative decisions made by the surgeon and radiation oncologist. For patients with locally recurrent rectal cancer undergoing surgery and intraoperative radiation therapy, intraoperative re-resection of positive margins to achieve negative margins is common practice. This study aimed to assess whether re-resection of positive margins found on intraoperative frozen-section analysis improves oncologic outcomes. This is a retrospective cohort study. This study was an analysis of a prospectively maintained multicenter database. All patients who underwent surgical resection of locally recurrent rectal cancer with intraoperative radiation therapy between 2000 and 2015 were included and followed for 5 years. Three groups were compared: initial R0 resection, initial R1 converted to R0 after re-resection, and initial R1 that remained R1 after re-resection. Grossly positive margin resections (R2) were excluded. The primary outcome measures were 5-year overall survival, recurrence-free survival, and local re-recurrence. A total of 267 patients were analyzed (initial R0 resection, n = 94; initial R1 converted to R0 after re-resection, n = 95; initial R1 that remained R1 after re-resection, n = 78). Overall survival was 4.4 years for initial R0 resection, 2.7 years for initial R1 converted to R0 after re-resection, and 2.9 years for initial R1 that remained R1 after re-resection ( p = 0.01). Recurrence-free survival was 3.0 years for initial R0 resection and 1.8 years for both initial R1 converted to R0 after re-resection and initial R1 that remained R1 after re-resection ( p ≤ 0.01). Overall survival did not differ for patients with R1 and re-resection R1 or R0 ( p = 0.62). Recurrence-free survival and freedom from local re-recurrence did not differ between groups. This study was limited by the heterogeneous patient population restricted to those receiving intraoperative radiation therapy. Re-resection of microscopically positive margins to obtain R0 status does not appear to provide a significant survival advantage or prevent local re-recurrence in patients undergoing surgery and intraoperative radiation therapy for locally recurrent rectal cancer. See Video Abstract at http://links.lww.com/DCR/B886 . ANTECEDENTES:El análisis de la ténica de criosección para los margenes positivos encontrados de manera intraoperatoria proporciona el estado de la resección del margen en tiempo real que puede guiar las decisiones intraoperatorias tomadas por el cirujano y el oncólogo radioterapeuta. Para los pacientes con cáncer de recto localmente recurrente que se someten a cirugía y radioterapia intraoperatoria, la re-resección intraoperatoria de los márgenes positivos para lograr márgenes negativos es una práctica común.OBJETIVO:Evaluar si la re-resección de los márgenes positivos encontrados en el análisis de la ténica por criosecciónde manera intraoperatorios mejora los resultados oncológicos.DISEÑO:Estudio de cohorte retrospectivo.AJUSTES:Análisis de una base de datos multicéntrica mantenida de forma prospectiva.POBLACIÓN:Todos los pacientes que se sometieron a resección quirúrgica de cáncer de recto localmente recurrente con radioterapia intraoperatoria entre 2000 y 2015 fueron incluidos y seguidos durante 5 años. Se compararon tres grupos: resección inicial R0, R1 inicial convertido en R0 después de la re-resección y R1 inicial que permaneció como R1 después de la re-resección. Se excluyeron las resecciones de márgenes macroscópicamente positivos (R2).PRINCIPALES MEDIDAS DE RESULTADO:Supervivencia global a cinco años, supervivencia sin recidiva y recidiva local.RESULTADOS:Se analizaron un total de 267 pacientes (resección inicial R0 n = 94, R1 inicial convertido en R0 después de la re-resección n = 95, R1 inicial que permaneció como R1 después de la re-resección n = 78). La supervivencia global fue de 4,4 años para la resección inicial R0, 2,7 años para la R1 inicial convertida en R0 después de la re-resección y 2,9 años para la R1 inicial que permaneció como R1 después de la re-resección ( p = 0,01). La supervivencia libre de recurrencia fue de 3,0 años para la resección inicial R0 y de 1,8 años para el R1 inicial convertido en R0 después de la re-resección y el R1 inicial que permaneció como R1 después de la re-resección ( p ≤ 0,01). La supervivencia global no difirió para los pacientes con R1 y re-resección R1 o R0 ( p = 0,62). La supervivencia libre de recurrencia y la ausencia de recurrencia local no difirieron entre los grupos.LIMITACIONES:Población de pacientes heterogénea, restringida a aquellos que reciben radioterapia intraoperatoria.CONCLUSIONES:La re-resección de los márgenes microscópicamente positivos para obtener el estado R0 no parece proporcionar una ventaja de supervivencia significativa o prevenir la recurrencia local en pacientes sometidos a cirugía y radioterapia intraoperatoria para el cáncer de recto localmente recurrente. Consulte Video Resumen en http://links.lww.com/DCR/B886 . (Traducción-Dr. Daniel Guerra ).

Intraoperative cytology (IC) is an alternative to frozen-section (FS) diagnosis. We present our experience with and the diagnostic value of IC during a 7-year period when FS was not available in a Peruvian Cancer Center.This 7-year retrospective single-arm review study includes IC procedures performed by three pathologists between 2012 and 2018. These IC reports were reviewed independently by one pathologist and were correlated with the histologic diagnoses, which were used as the gold standard. All IC preparations (imprint, scrape, and crush smears) were stained with hematoxylin and eosin. IC interpretations were categorized as: malignant, benign, atypical, and "deferred to permanent sections." Sensitivity, specificity, and positive and negative predictive values were calculated by use of standard methods.A total of 1814 IC cases prepared from various organs obtained from 887 patients were reviewed. Malignant, benign, atypical, and "deferred to permanent sections" IC diagnoses were 26.3%, 68.9%, 3.7%, and 1.9%, respectively. Atypical and deferred cases were excluded from the statistical analysis; thus 1712 cases were found to be eligible. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy were 91.6%, 97.7%, 94.1%, 96.7%, and 96%, respectively.In experienced hands, IC is a rapid, cost-effective, and accurate alternative diagnostic modality for intraoperative diagnosis when FS is not available.

An accurate evaluation of resection margin (RM) is critical in breast-conserving surgery (BCS) as negative RM status is critical for successful local control. We compared gross and microscopic methods for RM evaluation and analyzed their concordances.Gross evaluation (GE), frozen section analysis (FSA), and permanent section diagnosis (PSD) were compared for specimens from 725 breast cancer patients.The RM was grossly involved in 74 cases (10.2%). The sensitivity and specificity of GE were 22.9% and 96.1%, respectively. FSA revealed positive RM in 290 cases (40.0%), with high sensitivity (86.7%) and specificity (83.1%). With PSD, 240 cases (33.1%) showed RM involvement. Discordant results between gross and microscopic methods were observed in 104 cases (14.3%).Our observations of the low sensitivity of GE, high discordance rate between gross and microscopic methods, and high sensitivity and specificity of FSA support the necessity of intraoperative FSA for assessing RM status during BCS.

Despite recent improvements in diagnostic and surgical techniques in urological oncology, positive resection margin remains a significant concern for surgeons. Meanwhile, intraoperative pathology consultation with frozen section assessment (FSA), particularly for histological diagnosis of the lesions incidentally found or enlarged or sentinel lymph nodes, generally provides critical information which enables immediate decision making for optimal patient care. The intraoperative evaluation of surgical margins is also often requested, although there are some differences in its application between institutions and surgeons. Importantly, it remains to be determined whether intraoperative FSA indeed contributes to reducing the risk of final positive margins and thereby improving long-term patient outcomes. This review summarizes available data indicating the potential impact of FSA at the surgical margins during urological surgeries, including radical or partial cystectomy, partial nephrectomy, radical prostatectomy, penectomy, and orchiectomy. The accuracy and pitfalls of the intraoperative consultation/FSA diagnosis are also discussed.

Objective This study evaluated diagnostic accuracy of intraoperative sentinel lymph node (SLN) frozen section examination and scrape cytology as a possible solution for management of SLN positive patients. Study design Clinically early-stage endometrial cancer patients who underwent SLN algorithm and intraoperative SLN examination were analyzed. Findings were compared with final pathology results and diagnostic accuracy of frozen section and scrape cytology were evaluated. Results Of the 208 eligible patients, 100 patients (48 %) had frozen section examination and 108 (52 %) had scrape cytology of the SLN. Intraoperative examination and final pathology were negative for metastasis in 187/208 (90 %) cases. The rest 21 cases had metastatic SLNs according to final pathology. 12 of 21 (57 %) metastases were classified as macrometastasis. Intraoperative examination of SLNs correctly identified 13 cases (true positive) and missed 8 cases (false negative). Five of 8 false negative cases had micrometastasis or isolated tumor cells. Considering identification of macrometastasis, sensitivity and negative predictive value were 85.71 % and 98.94 %, respectively, for the frozen section and 60.00 % and 98.15 %, respectively, for the scrape cytology. Conclusion Frozen section examination of SLN has higher sensitivity in detecting macrometastasis compared to scrape cytology and it could help the surgeon in decision for further lymphadenectomy intraoperatively.

Background Surgeons utilize a combination of preoperative tests and intraoperative findings to diagnose periprosthetic joint infection (PJI); however, there is currently no reliable diagnostic marker that can be used in isolation. The purpose of our study is to evaluate the utility of frozen section histology in diagnosis of PJI. Methods Retrospective analysis of 614 patients undergoing revision total joint arthroplasty with frozen section histology from a single institution was performed. Discriminatory value of frozen section histology was assessed using univariate analysis and evaluation of area under the curve (AUC) of a receiver operating characteristic curve comparing frozen section histology results to the 2018 International Consensus Meeting (ICM) PJI criteria modified to exclude the histology component. Results The sensitivity of the frozen section histology was 53.6% and the specificity was 95.2%. There was 99.2% concordance between the permanent section and frozen section results. The receiver operating characteristic curve for frozen section yielded an AUC of 0.744 (95% confidence interval 0.627-0.860) and the modified ICM score yielded an AUC of 0.912 (95% confidence interval 0.836-0.988) when compared to the full score. The addition of frozen section histology changed the decision to infected in 20% of “inconclusive” cases but less than 1% of total cases. Conclusion In comparison to the modified ICM criteria, intraoperative frozen section histology has poor sensitivity, strong specificity, and acceptable overall discrimination for diagnosing PJI. This test appears to be of particular value for patients deemed “inconclusive” for infection using the remaining ICM criteria.

Purpose The interdisciplinary “Martinique-Principles” of four international professional societies concerned with the patient management of differentiated thyroid cancer (DTC) patients were agreed upon. Differences in perioperative diagnostics can lead to differences in clinical decision founding regarding the treatment of thyroid carcinoma. Our aim was to analyze the perioperative diagnostics of patients referred for postoperative I-131 therapy of DTC. Methods We retrospectively examined the data of 142 patients who were referred to our center for the first course of postsurgical I-131 therapy. We extracted data on perioperative diagnostics. Results Fine-needle biopsy (FNB) was performed in 27/142 patients. In 17 patients, FNB yielded findings suspicious of malignancy, in 3 patients a follicular lesion was reported. An intraoperative frozen section analysis was performed in 79/142 patients. 5/63 patients showed already a cytologically proven malignancy. In 10/79 patients, the frozen section had a nonmalignant result, although DTC was found on final assessment. In 2/79 patients, frozen section analysis was indecisive, although the final report confirmed DTC. In the remaining 67 patients, frozen section yielded DTC. Conclusions There is room for improvement in perioperative diagnostics surrounding thyroid surgery, currently many procedures are performed without adequate information on potential presence of thyroid cancer. More frequent use of FNB might be able to decrease the number of unnecessary thyroid surgeries, increased use of frozen section might decrease the number of second operations and might contribute to less discordance between experts in the field of DTC treatment.

At the time of intraoperative consultation, cytologic preparations including smears and imprints can be used in combination with frozen sections to increase diagnostic yield; however, these simple and rapid techniques are not adopted by all pathologists and their use varies considerably between institutions. In patients under investigation for suspected lymphoma, optimal triaging of tissue received fresh in pathology for lymphoma workup is paramount to maximize the odds of obtaining an accurate and clinically meaningful diagnosis and to avoid the need for additional procedures and delays in management, particularly in the current context in which core biopsies have become common practice as a first attempt to attain this goal. Imprint cytology is invaluable in this regard, also as these patients may not have a lymphoma but rather one of its clinical mimics. Herein, imprint cytology is used to approach fresh specimens received intraoperatively for lymphoma workup. More specifically, how these specimens are triaged for ancillary studies, such as flow cytometry, florescence in situ hybridization, or molecular analyses based on an interpretation of the touch imprints, is described. Detailed imprint cytological findings of typical benign and malignant lymphoid and nonlymphoid lesions are discussed and illustrated.

Keratin granulomas in the peritoneum are a rare finding with multiple etiologies and can be especially challenging for both the pathologist and the surgeon when these lesions are grossly visible. We report a case of a unique frozen section diagnostic scenario of evaluation of keratin granulomas in the peritoneum of a 47-year-old woman in the setting of multiple potential culprits: endometrial endometrioid adenocarcinoma following fertility sparing treatment, and a concurrent dermoid cyst. We discuss the various etiologies of keratin granulomas in the peritoneum, mechanism of their formation, diagnostic significance, as well as implications of fertility sparing treatments. To the best of our knowledge, this is the only case of keratin granulomas in the peritoneum with multiple distinct potential pathologic culprits as well the only case following fertility sparing treatment.

Background Achieving negative margins for melanoma in situ, lentigo maligna type can be challenging, particularly on cosmetically sensitive areas. Objective To assess the utility of intraoperative frozen section margin assessment using a teledermatopathology system in the treatment of head and neck lentigo maligna. Methods and materials Over a 6 year period, 96 patients with lentigo maligna had surgical excisions. The margins were assessed intraoperatively with frozen sections prepared in the manner used in Mohs surgery. The surgeon guided the frozen section slides around the margin while a dermatopathologist assessed the margin remotely. Results In 2/96 (2.1%) cases, the safety margin was positive (frozen sections were false negative). In 1 further case (1%) there was a recurrence of the melanoma 13 months following the excision. Conclusion The described method is effective in treating melanoma in situ, lentigo maligna type with clearance rates similar to previous studies for Mohs surgery.

Aims It can be extremely challenging to determine whether to perform reimplantation in patients who have contradictory serum inflammatory markers and frozen section results. We investigated whether patients with a positive frozen section at reimplantation were at a higher risk of reinfection despite normal ESR and CRP. Methods We retrospectively reviewed 163 consecutive patients with periprosthetic joint infections (PJIs) who had normal ESR and CRP results pre-reimplantation in our hospital from 2014 to 2018. Of these patients, 26 had positive frozen sections at reimplantation. The minimum follow-up time was two years unless reinfection occurred within this period. Univariable and multivariable logistic regression analyses were performed to identify the association between positive frozen sections and treatment failure. Results Treatment failure occurred in eight (30.77%) of the 26 PJI patients with positive frozen sections at reimplantation, compared with 13 (9.49%) of 137 patients with negative results. In the multivariate analysis, positive frozen section increased the risk of failure (odds ratio 4.70; 95% confidence interval (CI) 1.64 to 13.45). The mean number of months to reinfection was lower in the positive frozen section group than in the control group (p = 0.041). While there were nine (34.62%) patients with positive frozen section and 25 (18.25%) patients with negative frozen section who had prolonged antibiotic use (p = 0.042), the mean duration of antibiotic use was comparable in two groups. Synovial white blood cell count (p = 0.137) and polymorphonuclear leucocyte percentage (p = 0.454) were not associated with treatment failure in logistic regression model. Conclusion Positive frozen section at reimplantation was independently associated with subsequent failure and earlier reinfection, despite normal ESR and CRP levels pre-reimplantation. Surgeons should be aware of the risk of treatment failure in patients with positive frozen sections and carefully consider benefits of reimplantation. Cite this article: Bone Joint J 2021;103-B(5):916–922.