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Background: Merkel cell carcinoma (MCC) is a rare, aggressive, cutaneous tumour with high mortality and frequently delayed diagnosis. Clinically, it often manifests as a rapidly growing erythematous to purple nodule usually located on the lower extremities or face and scalp of elderly patients. There is limited available data on the dermoscopic findings of MCC, and there are no specific features that can be used to definitively diagnose MCC., Aim of the Study: Here, we aimed to summarize existing published literature on dermatoscopic and reflectance confocal microscopy (RCM) features of MCC., Materials and Methods: To find relevant studies, we searched the PubMed and Scopus databases from inception to April 12, 2023. Our goal was to identify all pertinent research that had been written in English. The following search strategy was employed: (" dermoscopy" OR " dermatoscopy" OR " videodermoscopy" OR " videodermatoscopy" OR " reflectance confocal microscopy") AND " Merkel cell carcinoma". Two dermatologists, DK and GE, evaluated the titles and abstracts separately for eligibility. For inclusion, only works written in English were taken into account., Results: In total 16 articles were retrieved (68 cases). The main dermoscopic findings of MCC are a polymorphous vascular pattern including linear irregular, arborizing, glomerular, and dotted vessels on a milky red background, with shiny or non-shiny white areas. Pigmentation was lacking in all cases. The RCM images showed a thin and disarranged epidermis, and small hypo-reflective cells that resembled lymphocytes arranged in solid aggregates outlined by fibrous tissue in the dermis. Additionally, there were larger polymorphic hyper-reflective cells that likely represented highly proliferative cells., Conclusion: Dermoscopic findings of MCC may play a valuable role in evaluating MCC, aiding in the early detection and differentiation from other skin lesions. Further prospective case-control studies are needed to validate these results., (© 2024. The Author(s).)

The purpose of this study was to investigate the diagnostic and prognostic value of 18 F-FDG PET/CT for surveillance imaging in patients treated for stage III Merkel cell carcinoma (MCC). Methods: This retrospective study included 61 consecutive stage III MCC patients who were clinically asymptomatic and underwent surveillance 18 F-FDG PET/CT. Findings were correlated with either pathology or clinical/imaging follow-up. The median follow-up period was 4.8 y. Statistical analyses were performed. Results: 18 F-FDG PET/CT detected unsuspected recurrences in 33% patients (20/61) with lesion-based sensitivity, specificity, and accuracy of 92%, 93%, and 93%, respectively. The mean ± SD SUV for malignant and benign lesions was 7.5 ± 3.9 and 3.8 ± 2.0, respectively. Unknown distant metastases, as first recurrence site, were noted in 12 of 61 patients. Those with positive disease on 18 F-FDG PET/CT within 1 y of definitive treatment had relatively worse overall survival ( P < 0.0001). After adjustment on stage, risk of death increased with a higher SUV max (hazard ratio for 1 unit = 1.17; P = 0.006) and with a higher number of positive lesions on 18 F-FDG PET/CT (hazard ratio for 1 additional lesion = 1.60; P < 0.001). Conclusion: Postdefinitive treatment surveillance 18 F-FDG PET/CT scanning detects unsuspected recurrences and has prognostic value. Inclusion of 18 F-FDG PET/CT within the first 6 mo after definitive treatment would be appropriate for surveillance and early detection of recurrence. Our data merit further studies to evaluate the prognostic implications., (© 2022 by the Society of Nuclear Medicine and Molecular Imaging.)

Purpose: The purpose of this study was to report the prevalence and imaging features of abdominal metastases from Merkel cell carcinoma (MCC) on computed tomography (CT) examinations., Materials and Methods: A total of 111 patients with MCC from two institutions were initially identified. Of these, 27 patients (27/111; 24.3%) had abdominal metastases from MCC present on CT examination. There were 19 men and 8 women with a mean age of 75  ± 10.8 (SD) years (age range: 46-92 years). CT examinations were retrospectively reviewed by two radiologists and analyzed quantitatively for the number and dimensions of abdominal metastases from MCC and qualitatively in terms of location, margins, contours, homogeneity, patterns of enhancement, vascular involvement and extension of metastases from MCC., Results: Fifteen patients (15/27; 56%) had abdominal metastatic disease at initial diagnosis and twelve (12/27; 44%) developed abdominal metastases during the course of the disease. The mean number of locations of abdominal metastases was 2.1 ± 1.12 (SD) (range: 1-5). Abdominal metastases involved abdominal lymph nodes (16/27; 59%), adrenal glands/kidneys/retroperitoneum (14/27; 52%), mesentery/peritoneum (13/27; 48%), liver (7/27; 26%) and pancreas (7/27; 26%). Vascular involvement was found in association with peritoneal/mesenteric metastases in 6/13 (46%) patients with intraperitoneal metastases or in association with abdominal lymph nodes in 4/16 (25%) patients. Ureteral encasement and/or dilatation was found in 4/14 (28%) patients with retroperitoneal metastases and 3/16 (19%) patients with abdominal lymph nodes. Metastases to the liver, pancreas, peritoneum, retroperitoneum and adrenal glands displayed internal enhancement during the arterial phase in 1/2 (50%), 4/5 (80%), 4/7 (57%) and 5/8 (62%) patients for whom arterial phase was available, respectively., Conclusion: Metastases from MCC have a prevalence of 24.3% on CT examination and may involve a variety of abdominal organs, mainly lymph nodes, peritoneal and retroperitoneal structures, but also the liver and pancreas. CT features of abdominal metastases from MCC include hypervascularity during the arterial phase of enhancement and eventually vascular and ureteral involvement., Competing Interests: Disclosure of interests The authors declare that they have no competing interest., (Copyright © 2021 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.)

Merkel cell carcinoma (MCC) is an aggressive skin cancer associated with a high risk of local recurrence and distant metastasis. Optimal care of this potentially life-threatening cancer is critical but challenging because: physicians are often unfamiliar with its management due to rarity, and MCC management remains controversial, in part because it is rapidly evolving across multiple specialties. While guidelines offer a broad overview of management, they are often not sufficient when making decisions for individual patients. Herein, we present a literature review as well as practical approaches adopted at our institutions for staging, surveillance and therapy of MCC. Each of these areas are discussed in light of how they can be appropriately customized for prevalent but challenging situations. We also provide representative examples of MCC patient scenarios and how they were managed by a multidisciplinary team to identify suitable evidence-based, individualized treatment plans.

Only 2-3.9% of pancreatic malignancies represent metastases from other sites, the most common origins being the lungs, kidneys, and gastrointestinal tract. Differentiating between primary and secondary lesions may be challenging with imaging techniques but EUS-guided FNA is a safe, accurate procedure for obtaining a tissue diagnosis. We report the case of a 70-year-old male who, following satisfactory treatment for a Merkel-cell carcinoma in the right groin, presented with jaundice and an indurated, vascularized, adherent nodule on the right thigh. Endoscopic ultrasound identified a mass at the pancreatic head as well as a perilesional adenopathy with no evidence of vascular involvement. FNA revealed cell proliferation, which was immunohistochemically positive for CD56, synaptophysin, and chromogranin, these findings being consistent with poorly-differentiated neuroendocrine carcinoma. Given the patient's history we considered this lesion to be a pancreatic metastasis of Merkel-cell carcinoma, which represents a rare finding.

Introduction: The incidence of malignant melanoma has been rising steadily over the past decades and Merkel cell carcinoma is a highly aggressive neuroendocrine skin tumor with a high mortality rate. Sentinel lymph node (SLN) biopsy is a recommended prognostic tool in primary cutaneous malignant melanomas of intermediate thickness and in all clinically node-negative Merkel cell carcinomas. The gold standard method for identification of SLNs is lymphoscintigraphy, which involves radioactive tracers. Indocyanine green-based near-infrared fluorescence imaging (NIRFI) has been also used for intraoperative SLN identification. We aim to evaluate the diagnostic sensitivity of the VisionSense VS3 NIRFI device for SNL identification. This device uses stereoscopic 3D high definition for both fluorescence and visible light imaging. Our hypothesis is that SLNs may be identified transcutaneously using fluorescent dye injections and NIRFI; therefore, obviating the need for lymphoscintigraphy in the future. METHODS AND ANALYSIS:: lymph node identification in skin malignancy using indocyanine green transcutaneously is a prospective diagnostic sensitivity study conducted at the Department of Plastic and Hand Surgery at the University Hospital Berne, Inselspital, Switzerland. The study aims at recruiting 93 patients (start date September 2017) to compare the accuracy of VisionSense VS3 camera at identifying SLNs transcutaneously with the current gold standard, lymphoscintigraphy. Moreover, a secondary objective is to determine if anatomical location of the SLN and patient factors (eg, body mass index, age) have an impact on the ability of VisionSense to detect SLNs when compared with the same gold standard., Trial Registration Number: ClinicalTrials.gov NCT03545334.

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Purpose: To detect the expression of programmed death-ligand 1 (PD-L1) in Merkel cell carcinoma (MCC) and to determine the prognostic influence of the PD-L1 expression., Methods: A total of 13 patients with MCC were retrospectively evaluated (12 patients with primary skin lesion, one patient was diagnosed as unknown primary MCC). All patients underwent surgical resection. PD-L1 was determinated by imunohistochemistry. Immunostaining results were evaluated semiquantitatively. The prognostic influence of the expression of PD-L1 on overall survival (OS) was calculated with the Kaplan-Meier method and log-rank test., Results: PD-L1 positivity was detected in 8 patients (61.5%), in all cases the result was 1+. PD-L1 negativity was shown in the remaining 5 patients. In patients with PD-L1 positivity median OS was 42.1 months (95% CI 9.3-42.1) compared with median OS of 9.4 months (95% CI 2.1-80.9) in the group of patients without PD-L1 positivity (p=0.417)., Conclusions: PD-L1 positivity was found in 61.5% of patients with MCC. No prognostic significance of PD-L1 expression for OS was demonstrated.

Competing Interests: Competing interests: None declared.

The authors present the case of a woman in the seventh decade of life with medical history of: left nephrectomy for renal tuberculosis and non-Hodgkin's lymphoma treated with chemotherapy (QT) and radiotherapy. She presented with a 2-month history of non-tender, left inguinal lymph node enlargement. Positron Emission Tomography (PET) - CT -scanshowed hypermetabolic inguinal and retroperitoneal lymphadenopathies, no primary tumour. On the second dermatological examination a pink, 2 cm plaque on the anterior left knee was noted. The histopathological analysis revealed Merkel cell carcinoma. The patient underwent two lines of systemic QT, with life-threatening toxicities limiting treatment. Followed overwhelming disease progression with lymphoedema and numerous skin metastases in the left lower limb. The patient received palliative care until death. The rare incidence of such neoplasia and its uncommon clinical presentation justifies reporting this case and highlights the importance of multidisciplinary teams in the management of cancer patients., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: Real-world evidence of charted treatment responses to cancer drug therapy was compared with medical record derived radiographic measurements of target lesions per Response Evaluation Criteria in Solid Tumors (RECIST)., Materials & Methods: 15 physicians treating 59 metastatic Merkel cell cancer (mMCC) patients contributed patient-level data. A comparison of medical record reported best response with radiographic measurements per RECIST of pre- and post-treatment target lesions., Results: RECIST response rates were significantly lower compared with medical record reported with a concordance of 43.2% (95% CI: 28.0-58.4%)., Conclusion: Subjective assessment of tumor response collected via traditional chart abstraction may overestimate benefit and limit the potential role of real-world evidence in value-based care research. The use of target lesion measurements presents an attractive alternative that better aligns with trial results.

Introduction Merkel cell carcinoma (MCC) is a rare cutaneous tumour that is clinically aggressive with a high local, regional, and distant metastatic potential. Cases Three male patients presented to University Hospital Limerick (UHL) in 2015 with cutaneous lesions of the thorax, buttock and forearm. Once MCC was confirmed, management included surgical wide local excision (WLE) with regional lymph node dissection followed by adjuvant radiotherapy. One patient is in remission. The second has residual locoregional lymph node disease and is undergoing annual CT surveillance. The third had distant metastatic disease and is deceased from an unrelated condition. Discussion This case series highlights the presentation and management of MCC. We also discus relevant guidelines. The management of MCC is complex and there is a need to establish local or national databases to identify and monitor patients with MCC.

Background: Patients with metastatic Merkel cell carcinoma (mMCC) who experience disease progression on immunotherapy have limited additional standard options. Given evidence of synergism between radiation therapy (RT) and immunotherapy, two patients progressing on PD-1 inhibition were referred for short-course RT., Case Presentation: Two patients were found to have progressive mMCC on PD-1 inhibitor therapy and were treated with single-fraction palliative RT. Both patients were observed to have local control at irradiated regions, as well as durable abscopal response at unirradiated, out-of-field, sites of metastatic disease., Conclusions: Short-course RT is a compelling strategy that could be a means to augment response in patients with mMCC who show progression on immune checkpoint blockade. Ongoing clinical trials are investigating the relationship between RT and immunotherapy in mMCC.

Purpose: To develop a technique for radiation (RT) of in-transit path ways (IT) in Merkel cell carcinoma., Method: In the planning study, IT were ink-marked on the skin during sentinel lymphscintigraphy and wire-marked in planning-CT. Pre- and post-operative planning-CTs were acquired. The clinical target volume (CTV) included tumor bed plus safety margin, IT and draining nodes, the planning volume (PTV) the CTV plus 0.5-1cm margin. VMAT plans with 2-3 arcs were analyzed., Results: A planning study was performed for five pts. including two pts. with primary tumor (PT) in head and neck, 1 pt. each with PT of elbow, forearm and upper leg respectively. Plans showed satisfactory PTV coverage: D mean 100%±0%, D 98% 92.4%±2.24%, homogeneity index (HI) 0.095±0.01, conformation number (CN) 0.84±0.01 and conformality index (CI) 0.95±0.01., Conclusion: The planning study confirms feasibility of highly conformal irradiation of IT pathways based on individualized target delineation. Currently, patients referred for non-metastatic MCC are encouraged to enroll in a prospective clinical study that evaluates the feasibility of radiation of IT pathways., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Merkel cell carcinoma, though rare, is one of the most aggressive tumors a dermatologist faces. More than a third of patients with this diagnosis die from the disease. Numerous researchers have attempted to identify clinical and pathologic predictors to guide prognosis, but their studies have produced inconsistent results. Because the incidence of Merkel cell carcinoma is low and it appears in patients of advanced age, prospective studies have not been done and no clear treatment algorithm has been developed. This review aims to provide an exhaustive, up-to-date account of Merkel cell carcinoma for the dermatologist. We describe prognostic factors and the imaging techniques that are most appropriate for evaluating disease spread. We also discuss current debates on treating Merkel cell carcinoma., (Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.)

Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma of the skin with an aggressive clinical course. Although anthracycline- and platinum-based regimens are empirically used as first-line treatments for metastatic or unresectable cases, no salvage therapy has been established. A 73-year-old man with platinum-refractory recurrent MCC was treated with amrubicin. The symptoms improved soon, and a partial response was achieved. A total of nine cycles of amrubicin were administered in nine months with manageable adverse events until disease progression was finally observed. The present findings suggest the potential of amrubicin monotherapy as a second-line therapy for patients with advanced/recurrent MCC.

This report illustrates an excellent partial response of Merkel cell carcinoma with multiple bilobar hepatic metastases to a single cycle of peptide receptor radionuclide therapy (PRRT) with (177)Lu-DOTATATE. This response, coupled with minimal side effects, warrants consideration of this therapy early in the disease course (rather than at an advanced stage after failure of other therapies) if the metastatic lesions exhibit adequate tracer avidity on somatostatin receptor-based imaging. Our patient showed progression of systemic disease after having undergone a second surgery and adjuvant radiotherapy to the head and neck, as well as chemotherapy, and hence was considered a candidate for PRRT. In a pretreatment study, the metastatic lesions demonstrated avidity to both somatostatin receptors and (18)F-FDG. Three months after the first cycle of treatment, when the patient was being evaluated for a second cycle, both imaging parameters showed evidence of a partial response that included nearly complete resolution of the two previously seen lesions. In view of the relatively good tolerability, minimal side effects, and targeted nature of the treatment, PRRT may evolve to become the first-line therapy for metastatic Merkel cell carcinoma and should be examined further in a larger number of patients., (© 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)

Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma of the skin with unpredictable evolution and high metastatic potential. This neoplasm usually occurs in the elderly on their sun-exposed areas. CCM constant greed for 18 fluorodeoxyglucose (FDG) defines the role of positron emission tomography (PET) in this pathology. However, no consensus has yet been reached. This study reports the case of a 25 year old woman treated for metastatic MCC, in order to draw attention to this particular tumor and to illustrate the role of 18 FDG PET in the management of this rare entity.

Sentinel node mapping is an integral part of regional lymph node staging in many solid tumors and plays an important role in surgical oncology. This technique has been used with excellent results for non-melanoma skin cancers including Merkel Cell Carcinoma (MCC). In the current study, we reported our first MCC patient who underwent successful sentinel node mapping. We also reviewed the available literature regarding the prognostic significance of sentinel node mapping in cN0 MCC patients.

Unlabelled: The objective of this study was to evaluate the utility of (18)F-FDG PET in restaging and response assessment of patients who underwent definitive treatment for Merkel cell carcinoma (MCC)., Methods: A retrospective review of patients undergoing (18)F-FDG PET imaging for MCC between January 1997 and October 2010 at the Peter MacCallum Cancer Centre with follow-up until February 2015 was performed. Data analysis was performed on patients who were treated definitively and underwent post-treatment PET imaging performed either as a restaging scan for ongoing monitoring, suspicion of recurrence, or assessment for suitability of salvage treatment or as response assessment within 1-6 mo of treatment. Management plans were recorded prospectively before (18)F-FDG PET imaging and compared with post-imaging management to assess the impact of the study as per our previously defined categories: high if the primary treatment modality or intent was changed and medium if the radiotherapy technique or dose was altered. In total, 62 patients were included in the analysis. Thirty-six patients underwent 53 restaging scans, and 37 patients underwent a response-assessment scan. The median follow-up of patients in the restaging group was 5.3 y (95% confidence interval [CI], 4.6-9.4), and it was 5.7 y (95% CI, 4.3-10.8) in the response-assessment group., Results: Restaging (18)F-FDG PET scans had a high impact in 24 of 53 cases (45%) and a medium impact in 6 of 53 cases (11%). In the response-assessment group, 24 of 37 patients had a complete metabolic response (CMR). Patients without a CMR had a 15% 1-y overall survival (95% CI, 0.04-0.55). Those with a CMR had an 88% 2-y overall survival (95% CI, 0.75-1.00) and a 68% 5-y overall survival (95% CI, 0.49-0.95). The presence of a CMR (P < 0.001) and nodal involvement (P = 0.016) were statistically significant prognostic factors for overall survival., Conclusion: (18)F-FDG PET imaging had a high impact on restaging after definitive treatment in patients with MCC. Metabolic response was significantly associated with overall survival. (18)F-FDG PET may play an important role in ongoing post-treatment management of MCC., (© 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)

Introduction: A retrospective preliminary study assessed the feasibility of sentinel lymph node biopsy (SLNB) in the management of Merkel cell carcinoma (MCC) of the head and neck., Patients and Methods: Twelve patients with stage I or II head and neck MCC underwent SLNB over a 4-year period., Results: Only 1 of the 12 patients had a positive SLNB. The sentinel node was not identified in 3 patients. Two of the 8 patients with negative SLNB showed regional lymph node recurrence within 2years. One patient died during follow-up., Conclusion: Merkel cell carcinoma is an uncommon but highly aggressive pathology; management protocols have been based on small series. The role of SLNB in the management of MCC remains to be defined., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Background: Merkel cell carcinoma (MCC) is a rare cutaneous neoplasm with increasing incidence, aggressive behavior and poor prognosis. Somatostatin receptors (SSTR) are expressed in MCC and represent a potential target for both imaging and treatment., Methods: To non-invasively assess SSTR expression in MCC using PET and the radiotracers [68Ga]DOTA-D-Phe1-Tyr3-octreotide (DOTATOC) or -octreotate (DOTATATE) as surrogate for tumor burden. In 24 patients with histologically proven MCC SSTR-PET was performed and compared to results of computed tomography (CT)., Results: SSTR-PET detected primary and metastatic MCC lesions. On a patient-based analysis, sensitivity of SSTR-PET was 73% for nodal metastases, 100% for bone, and 67% for soft-tissue metastases, respectively. Notably, brain metastases were initially detected by SSTR-PET in 2 patients, whereas liver and lung metastases were diagnosed exclusively by CT. SSTR-PET showed concordance to CT results in 20 out of 24 patients. Four patients (17%) were up-staged due to SSTR-PET and patient management was changed in 3 patients (13%)., Conclusion: SSTR-PET showed high sensitivity for imaging bone, soft tissue and brain metastases, and particularly in combination with CT had a significant impact on clinical stage and patient management.

Unlabelled: Merkel cell carcinoma (MCC) is a rare but aggressive skin cancer with limited evidence on the role of PET scanning. The primary aim of this study was to assess the impact of (18)F-FDG PET in the staging and management of MCC., Methods: A single-institution review using clinical outcome data collected until February 2012 was performed of patients with MCC who underwent staging PET scanning between January 1997 and October 2010. Management plans were recorded prospectively at the time of the PET request, and follow-up outcomes were recorded retrospectively. The clinical impact of PET was scored using our previously published criteria: "high" if the PET scan changed the primary treatment modality or intent; "medium" if the treatment modality was unchanged but the radiation therapy technique or dose was altered. The primary objective was to test the hypothesis that the true proportion of patients who have a high- or medium-impact scan would be greater than 25%., Results: The median follow-up of 102 consecutive patients was 4.8 y. The results of staging PET had an impact on patient management in 37% of patients (P < 0.003). High- and medium-impact scans were recorded for 22% and 15% of patients, respectively. PET staging results differed from conventional staging results in 22% of patients, with PET upstaging 17% and downstaging 5%. The 3- and 5-y overall survival was 60% (95% confidence interval, 50%-71%) and 51% (95% confidence interval, 41%-64%), respectively. In stratification by PET-defined stage, the 5-y overall survival was 67% for patients with stage I/II disease but only 31% for patients with stage III disease (log-rank P < 0.001). The 5-y cumulative incidence of locoregional failure, distant failure, and death was 16.6%, 22.3% and 14.3%, respectively. On multivariate analysis, only PET stage (P < 0.001) and primary treatment modality (P = 0.050) were significantly associated with overall survival. The primary treatment modality was not associated with progression-free survival when stratification was by tumor stage., Conclusion: The use of (18)F-FDG PET scans had a great impact on patients and may play an important role in the prognostic stratification and treatment of this disease.

Few studies have been published on the safety and feasibility of synchronous use of peptide receptor radionuclide therapy (PRRNT), as source of internal radiation therapy, in combination with chemotherapy. In this study we reported a 53-year-old man with stage IV Merkel cell carcinoma (MCC), who underwent synchronous internal radiation therapy and chemotherapy. Based on presumable poor prognosis with chemotherapy only, functional similarities of MCC with other neuroendocrine tumors and available evidence of effectiveness and safety of synchronous use of external beam radiation therapy and chemotherapy in treatment of high-risk MCC patients, our interdisciplinary neuroendocrine tumor board recommended him to add PRRNT to his ongoing chemotherapy. He received 2 courses of (177)Lu-DOTATATE(1, 4, 7, 10-Tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid-1-D-Phe1-Tyr3-Thr8-octreotide) in combination with ongoing 8 cycles of liposomal doxorubicin based on standard protocols. Response to therapy was evaluated by (18)F-FDG and (68)gallium-somatostatin-receptor PET/CT. There was an impressive improvement of the clinical symptoms. However, follow-up PET/CT studies showed mixed pattern of response. Synchronous use of PRRNT and radiosensitizing chemotherapy seems safe and feasible in high risk MCC patients, however, further prospective studies and clinical trials are warranted to provide reliable evidence of possible pitfalls and effectiveness of PRRNT and (68)Ga-somatostatin-receptor PET/CT in the management of MCC.

Sentinel lymph node biopsy is performed routinely in melanoma because lymph node progression has been shown to be the strongest predictor of survival. Given the proven relevance of biopsy findings in this type of skin cancer, the procedure has been extended to other skin tumors. Experience in nonmelanoma cancer is much more limited and the prognostic usefulness of biopsy results remains to be shown. This critical review of the literature on the various skin tumors in which sentinal node biopsy has been practiced discusses the usefulness of this procedure., (Copyright © 2010 Elsevier España, S.L. y AEDV. All rights reserved.)

The Merkel cell carcinoma is a rare, serious, neuroendocrine, malignant skin cancer with lymph node involvement in half of patients and disseminated metastases in 20% of cases at the time of pathological diagnosis. Its treatment is not fully established, though the sentinel lymph node has been considered essential and may bring benefits to the therapeutic armamentarium of patients.

Merkel cell carcinoma is a rare form of skin cancer of likely neuroendocrine origin wich affects mainly white population in sun-exposed areas. It is an aggressive tumor and survival is dependent on stage at the time of diagnosis. The staging evaluation include CT imaging and recently PET scan. Surgical excision with or without lymph node dissection, followed by postoperative radiotherapy in stage II disease, is the standard treatment of non metastatic disease. The role of adjuvant chemotherapy is still controversial. In patients with metastatic disease, chemotherapy regimens active in small cell lung cancer are generally used. The combination of cyclophosphamide, doxorubicin and vincristine (CAV) has an overall response rate of 75%, whereas the response rate of etoposide in combination with cisplatin or carboplatin is 60%. Experience with other therapeutic agents, such as tumor necrosis factor, interferon and octreotide is scanty. Recently, encouraging preliminary results with targeted agents have been reported. Our experience in 14 patients, four of whom treated with chemotherapy for advanced disease, is in agreement with literature

Background: Merkel cell carcinoma (MCC) is a rare and aggressive skin tumour with a highly malignant nature whose appropriate treatment is still debated. The Authors report a case of cutaneous metastasis from neuroendocrine carcinoma and analyse new diagnostic and therapeutic options of neoplasms that occurs in sun-exposed areas., Methods: The authors present the clinical, immunocytochemical characteristic of primary and secondary skin localization of a neuroendocrine tumor that affected a woman., Results: Histological and immunocytochemical analysis demonstrated that the secondary cutaneous localization appeared to be compared to the primary tumour., Conclusions: The case confirm the high incidence of regional metastasis; a wide surgical excision of tumor and regional lymphadenectomy is therefore recommended for primary treatment of MCC; the radiation treatment minimized the local recidives with long time survival.

A 63-year-old man was diagnosed with metastatic MCC. Preliminary staging PET scan with 18F-FDG was not done at the time of diagnosis. After completion of chemo- and radiotherapy, the patient underwent a CT scan of the area from the maxilla to the ischium; no evidence of disease was noted. Clinically, the patient was considered to be in remission. The CT scan was followed by head-to-toe FDG-PET scanning which revealed foci of metastatic disease in the right mid- thigh and left proximal calf. This case demonstrates the added value of head-to-toe FDG-PET for the detection of distant metastases in MCC.

Background: Somatostatin receptor scintigraphy (SRS) may be of interest for staging Merkel Cell Carcinoma (MCC). This study was undertaken to evaluate the sensitivity and specificity of SRS and to determine its role compared to conventional investigations., Patients and Methods: From 1993 to December 2000, 20 patients (10 females and 10 males, aged from 38 to 88, mean 66 years) were included prospectively. At the time of SRS: 12 patients had been diagnosed as having stage I disease, 6 stage II and 4 stage III. Two patients had two SRS studies during the course of their disease. SRS was performed with Indium-111 pentetreotide (Octreoscan), a radiolabelled somatostatin analogue. Patients were treated according to the clinical stage. A regular follow-up was scheduled every three months., Results: SRS depicted stage I and II MCC tumour sites with an overall sensitivity of 78% (95% confidence interval (CI): 40%-97%) and a specificity of 96% (81%-100%). The histopathological diagnosis was used as the gold standard. Sites visualised by SRS were compared to those detected with conventional modalities and to follow-up data for all stages: SRS visualised four out of five primary tumour sites, six out of eight lymph node sites, no skin metastases (14 sites in 2 patients), two out of three thoracic metastases and zero out of two hepatic metastases. SRS did not influence treatment decision-making in any of the cases., Conclusions: Although SRS seems highly specific in MCC and could be of help in difficult cases, it cannot be recommended for routine evaluation.

An 87-yr-old woman diagnosed with recurrent Merkel's cell carcinoma was treated with therapeutic limb perfusion and underwent PET scanning with 18F-fluorodeoxyglucose (FDG). PET studies were obtained before and after treatment to determine the response to the intervention. A baseline whole-body study was obtained to assess the extent and degree of disease activity. This was followed by a repeat PET scan 2 mo. later after treatment with isolated limb chemotherapy with high-dose melphalan and tumor necrosis factor-alpha. The initial scan demonstrated multiple foci of high FDG uptake in the left calf, a left supraclavicular lesion and also detected concurrent keratinizing squamous cell metastasis in the right axilla. A repeat PET study showed complete metabolic resolution of the lesions in the left calf after treatment. FDG PET may be a useful technique for staging Merkel cell carcinoma and for assessing the tumor response after therapy of this rare tumor.