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* Context.--Most laboratories currently use patient tissues for validating immunohistochemical stains. Objective.--To explore advantages of using cell lines with known antigenicity as a validation method. Design.--Five American Type Culture Collection (ATCC) cell lines with known negative, low positive, and moderate to strong estrogen receptor (ER) expression as well as negative, equivocal, and positive human epidermal growth factor receptor 2 (HER2) expression were cultured and made into cell blocks. One block from each cell line was fixed in formalin and another in ethanol before cell block preparation. Two sets of paired unstained slides from each block were sent to 10 different laboratories for HER2 and ER staining to be stained on runs from different days according to each laboratory's defined protocol. Results.--The 10 study participants evaluated 40 slides in a blinded fashion. For ER expression, all 80 interpretations for the ER strong and moderate positive cell lines had the target ER-positive result, and 74 of 80 ER-negative cell lines (92.5%) had agreement with the intended negative result. The ER low positive cell line showed varied but positive expression among all observers. The HER2 (3+)positive cell lines yielded a target interpretation of 3+ in 65 of 80 interpretations (81.2%). For the HER2-negative cell line 69 of 78 interpretations (88.5%) were consistent with the target response (0 or 1+). No significant variation was observed between the ethanol- and non-ethanol-exposed cell lines, or between runs by the same laboratory. Variation from target results clustered within laboratories. Conclusions.--This study indicates that variability between laboratories can be identified by using cell lines for quantitative or semiquantitative immunohistochemistry when using cultured cell lines of known antigenicity. These cell lines could potentially play a role in aiding anatomic pathology laboratories in validating immunohistochemistry tests for formalin- and ethanol-fixed tissues. doi: 10.5858/arpa.2021-0152-CP, Reliable immunohistochemical stain results are often a needed aid in the diagnostic assessment of anatomic pathology cases. Furthermore, as the sophistication of tumor subtyping has continued to evolve, most IHC [...]

* Context.--Repair is a challenging diagnosis and a significant source of false-positive (FP) interpretations in cervical cytology. No large-scale study of performance of repair in the liquid-based era has been performed. Objective.--To evaluate the performance of repair in the College of American Pathologists Pap Education and Proficiency Testing (PT) programs. Design.--The FP rate for slides classified as repair was evaluated by preparation type, participant type (cytotechnologist, pathologist, or laboratory), and program. The specific misdiagnosis category and individual slide performance were also evaluated. The rate of misclassification of slides as repair by participants for other diagnostic categories in the Pap Education program was assessed. Results.--The overall FP rate was 1700 of 12 715 (13.4%). There was no significant difference by program or preparation type. Within the Education program there was no difference by participant type, but pathologists' FP rate in the PT program (47 of 514, 9.1%) was significantly better than cytotechnologists in the PT program (51 of 380, 13.4%) and pathologists in the Education program (690 of 4900, 14.1%). High-grade squamous intraepithelial lesions/cancers ([HSIL.sup.+]) accounted for 1380 of 1602 FP interpretations (86%) in Education, but 43 of 98 (43.9%) in PT. Most slides had a low rate of misclassification, but a small number were poor performers. False-negative diagnosis of [HSIL.sup.+] as repair was less common, ranging from 0.7% to 1.8%. Conclusions.--Despite initial indications that liquid-based cytology might reduce the rate of misclassification of repair, FP interpretations remain common and are no different by preparation type. Misclassification is most commonly as HSIL or carcinoma, potentially resulting in significant patient harm. (Arch Pathol Lab Med. 2020;144:846-852; doi: 10.5858/arpa.2019-0298-CP), Repair, or reparative changes, refers to a specific pattern of changes in cervical cells attributed to injury from an external stimulus. (1-4) Although repair shows some morphologic overlap with dysplastic [...]

* Context.--The Paris System for Reporting Urinary Cytology has been disseminated since its inception in 2013; however, the daily practice patterns of urinary tract cytopathology are not well known. Objective.--To assess urinary tract cytopathology practice patterns across a variety of pathology laboratories to aid in the implementation and future update of the Paris System for Reporting Urinary Cytology. Design.--A questionnaire was designed to gather information about urinary tract cytopathology practices and mailed in July 2014 to 2116 laboratories participating in the College of American Pathologists interlaboratory comparison program. The participating laboratories' answers were summarized. Results.--Of the 879 of 2116 laboratories (41%) that participated, 745 (84.8%) reported processing urinary tract specimens in house. The laboratories reported processing various specimen types: voided urine, 735 of 738 (99.6%); bladder washing/barbotage, 639 of 738 (86.6%); and catheterized urine specimens, 653 of 738 (88.5%). Some laboratories used multiple preparation methods, but the most commonly used preparation techniques for urinary tract specimens were ThinPrep (57.4%) and Cytospin (45.5%). Eighty-eight of 197 laboratories (44.7%) reported preparing a cell block, but with a low frequency. Adequacy criteria were used by 295 of 707 laboratories (41.7%) for voided urine, and 244 of 707 (34.5%) assessed adequacy for bladder washing/ barbotage. More than 95% of the laboratories reported the use of general categories: negative, atypical, suspicious, and positive. Polyomavirus was classified as negative in 408 of 642 laboratories (63.6%) and atypical in 189 of 642 (29.4%). One hundred twenty-eight of 708 laboratories (18.1%) performed ancillary testing, and of these, 102 of 122 (83.6%) reported performing UroVysion. Conclusions.--Most laboratories use the ThinPrep method followed by the Cytospin technique; therefore, the criteria published in The Paris System for Reporting Urinary Cytology, based mostly on ThinPrep and SurePath, should be validated for Cytospin, and relevant information should be included in the revised edition of The Paris System for Reporting Urinary Cytology. (Arch Pathol Lab Med. 2020;144:172-176; doi: 10.5858/arpa.2019-0045-CP), Urine cytology comprises a variable, albeit significant, percentage of daily nongynecologic case volume in many cytopathology practices and continues to be one of the more difficult specimens that pathologists encounter [...]

* Context.--Obtaining diagnostic concordance for squamous intraepithelial lesions in cytology can be challenging.Objective.--To determine diagnostic concordance for biopsy-proven low-grade squamous intraepithelial lesion (LSIL) and high-grade squamous intraepithelial lesion (HSIL) Papanicolaou test slides in the College of American Pathologists PAP Education program.Design.--We analyzed 121 059 responses from 4251 LSIL and HSIL slides for the interval 2004 to 2013 using a nonlinear mixed-model fit for reference diagnosis, preparation type, and participant type. We evaluated interactions between the reference diagnosis and the other 2 factors in addition to a repeated-measures component to adjust for slide-specific performance.Results.--There was a statistically significant difference between misclassification of LSIL (2.4%; 1384 of 57 664) and HSIL (4.4%; 2762 of 63 395). There was no performance difference between pathologists and cytotechnologists for LSIL, but cytotechnologists had a significantly higher HSIL misclassification rate than pathologists (5.5%; 1437 of 27 534 versus 4.0%; 1032 of 25 630; P = .01), and both were more likely to misrepresent HSIL as LSIL (P < .001) than the reverse. ThinPrep LSIL slides were more likely to be misclassified as HSIL (2.4%; 920 of 38 582) than SurePath LSIL slides (1.5%; 198 of 13 196), but conventional slides were the most likely to be misclassified in both categories (4.5%; 266 of 5886 for LSIL, and 6.5%; 573 of 8825 for HSIL).Conclusions.--More participants undercalled HSIL as LSIL (false-negative) than overcalled LSIL as HSIL (false-positive) in the PAP Education program, with conventional slides more likely to be misclassified than ThinPrep or SurePath slides. Pathologists and cytotechnologists classify LSIL equally well, but cytotechnologists are significantly more likely to undercall HSIL as LSIL than are pathologists.doi: 10.5858/arpa.2018-0003-CP), The College of American Pathologists (CAP) Cytopathology Committee maintains and administers the PAP Education (PAP Ed) program, which provides 2 mailings of 5 glass slide Papanicolaou (Pap) tests annually to [...]

Context.--Nongynecologic cytology (NGC) practices are expanding in relationship to historical gynecologic cytology screening programs. Bronchopulmonary cytology is experiencing an evolution regarding new procedural types. The College of American Pathologists (CAP) tracks practice patterns in NGC by developing questionnaires, surveying participants, and analyzing respondent data. Objective.--To analyze responses to a 2013 CAP supplemental survey from the Interlaboratoy Comparison Program on bronchopulmonary NGC. Design.--The 'NGC 2013 Supplemental Questionnaire: Demographics in Performance and Reporting of Respiratory Cytology' was mailed to 2074 laboratories. Results.--The survey response rate was 42% (880 of 2074) with 90% of respondents (788 of 880) indicating that their laboratories evaluated cytology bronchopulmonary specimens. More than 95% of respondents indicated interpreting bronchial washings (765 of 787) and bronchial brushings (757 of 787). A minority of laboratories (43%, 340 of 787) dealt with endobronchial ultrasound-guided samples, and an even smaller fraction of laboratories (14%, 110 of 787) saw cases from electromagnetic navigational bronchoscopy. Intraprocedural adequacy assessments by pathologists (and less often by cytotechnologists or pathologists-in-training) were routinely performed in percutaneous transthoracic aspiration cases (74%, 413 of 560) with less involvement for other case types. Most laboratories reported that newly diagnosed primary pulmonary adenocarcinomas were triaged for molecular testing of epidermal growth factor receptor and anaplastic lymphoma kinase. Conclusions.--The parameters examined in this 2013 survey provide a snapshot of current pulmonary cytopathology practice and may be used as benchmarks in the future. (Arch Pathol Lab Med. 2016; 140:22-28; doi: 10.5858/arpa.2014-0635-CP), The Cytopathology Committee (CC) of the College of American Pathologists (CAP) creates questionnaires and conducts surveys that are designed to assess current cytology laboratory practices. Early surveys from the CAP [...]

Context.--Although the cytomorphology of adenoid cystic carcinoma (ACC) has been well described, the accuracy of this diagnosis in fine-needle aspirates (FNAs) of the salivary glands has not been extensively evaluated. Objective.--To assess participants' responses in the College of American Pathologists (CAP) Nongynecologic Cytology (NGC) Program to determine the accuracy and false-negative rate of ACC cases in salivary gland FNAs. Design.--A retrospective review of the CAP NGC Program's cumulative data from 2000-2010 was performed for the general and the specific reference diagnosis categories for ACC in salivary gland FNAs according to preparation and participant types. Results.--Of 5156 responses, the overall concordance rates for both the general category of malignancy and the specific category of ACC were 63.6% (3279 of 5156) and 38.6% (1966 of 5088), respectively, with a false-negative rate of 36.4% (1877 of 5156). The most frequent false-negative responses were pleomorphic (1080) and monomorphic (526) adenoma (1614 of 5088, 31.5%), while lymphoma was the most frequent malignant misinterpretation. There was a significant statistical difference in concordance to the reference interpretation between the reader types: 39.9% (1006 of 2521) concordance rate for pathologists compared to 33.8% (503 of 1488) for cytotechnologists. However, there was no significant statistical difference for concordance to the general category or reference interpretation, based on preparation type (Papanicolaou versus modified Giemsa stained). Conclusions.--In this interlaboratory comparison educational program, accurate identification of ACC has shown to be problematic, with ACC representing an important cause of false-negative responses. The most common diagnostic pitfall is distinguishing this entity from pleomorphic and monomorphic adenoma in the benign category and from lymphoma and adenocarcinoma in the malignant one. (Arch Pathol Lab Med. 2015; 139:1525-1530; doi: 10.5858/arpa.2013-0173-CP), Adenoid cystic carcinoma (ACC) is a relatively rare, slow-growing, malignant salivary gland tumor with poor long-term prognosis. (1) Cytologic features of ACC have been well described (2-14); however, the reproducibility [...]

Context.--Pulmonary bronchial brushing specimens can be processed by liquid-based or conventional methods. The ability to accurately diagnose a pulmonary malignancy with a liquid-based preparation (LBP) versus a conventional preparation may differ. Objective.--To compare the performance of LBPs of malignant pulmonary bronchial brushing specimens with the performance of conventional preparations. Design.--Participant responses from 553 malignant pulmonary bronchial brushing samples were evaluated for concordance with the general diagnosis. The performance of LBPs was compared with that of classic preparations. A nonlinear mixed model was used to analyze the performance by reference diagnosis, preparation type, program years, participant type, and the interaction terms between these 4 factors. Results.--Concordance with the general category of malignant disease was observed in 95.2% of conventional Papanicolaou-stained, 90.9% of modified Giemsa-stained, and 96.9% of LBP (P < .001) samples. The results were significantly different between individual reference diagnoses (P < .001). The performance of LBPs was consistently higher for most diagnoses and was significantly better for squamous cell carcinoma (P = .005), small cell carcinoma (P < .001), and metastatic carcinoma not otherwise specified (P < .001). All participant types performed significantly better with LBPs of small cell carcinoma. Pathologists and cytotechnologists performed significantly better with LBPs of squamous cell carcinoma. A significantly higher concordance was observed between the general diagnosis and program years 2007-2011 versus 2001-2006 (P = .006). Conclusions.--Liquid-based preparations performed better than conventional methods, with significantly higher performance in squamous cell, small cell, and metastatic carcinomas. Improved performance over time may reflect more frequent use of LBP methods and increased familiarity with interpreting the morphologic findings. (Arch Pathol Lab Med. 2015; 139:178-183; doi: 10.5858/arpa.2013-0282-CP), Pulmonary bronchial brushing (BB) is one of the most sensitive cytological procedures for diagnosing lung cancer. (1-3) Specimens obtained by BB can be processed by conventional methods or by liquid-based [...]

* Context.--Nongynecologic cytology (NGC) practices are expected to expand relative to gynecologic cytology. The College of American Pathologists attempts to track practice patterns in NGC using a self-reported questionnaire. Objective.--To analyze self-reported laboratory staffing and practices from a 2010 survey relating to NGC specimens, stains, preparation, procedures, and ancillary testing. Design.--The 'NGC 2010 Demographics and Supplemental Questionnaire: Current Nongynecologic Practices in Cytopathology Laboratories' was mailed to 2059 laboratories. Results.--Survey response rate was 51% (1048 of 2059), predominantly from voluntary, nonprofit hospitals, where NGC samples were reviewed in nontraining settings by pathologists without American Board of Pathology Added Qualification in Cytopathology. Cytotechnologists reviewed NGC cases in 67.4% (675 of 1002) of laboratories. The annual mean and median volumes of NGC cases were 1927 and 858, respectively. Laboratories used more than one method to process NGCs; cell-blocks were most frequently used (930 of 1029; 90.4%) and were created with centrifugation to pellet (538 of 961; 56%). Direct smears were second in preparation frequency; discrete staining was preferred to batch staining. Nongynecologic cytology was used for molecular studies in 34.9% (350 of 1002) of laboratories, most commonly for fluorescent in situ hybridization of urine specimens. Flow cytometric immunophenotyping was performed by 55.9% (554 of 991) and immunohistochemistry by 91.9% (911 of 991) of the responding laboratories. Most laboratories (911 of 993; 91.7%) report specimen completion in 2 or fewer days. Cytohistologic correlation was performed by 71.6% (722 of 1008) of the laboratories both concurrently and retrospectively. Conclusion.--The various parameters examined in the 2010 survey provide a benchmark for future efforts in quality assurance and process improvement in NGC. (Arch Pathol Lab Med. 2014; 138:885-889; doi: 10.5858/arpa.2012-0680-CP), Since the inception of the Interlaboratory Comparison Program in Cervicovaginal Cytology (the PAP Education program) in 1997, the Cytopathology Committee of the College of American Pathologists (CAP) has been regularly [...]