Objective:To investigate the clinicopathological features, differential diagnosis and prognosis of Merkel cell carcinoma (MCC).Methods:The clinical and pathological data of 10 patients with MCC were collected at the 940th Hospital of PLA. The histological characteristics were examined. Immunohistochemical EnVision method was used to detect thyroid transcription factor-1 (TTF1), broad-spectrum cytokeratin (CKpan), CK20, S-100, Ki-67, CD56, chromogranin A, synaptophysin and other markers in the 10 cases.Results:Intradermal MCC of the skin showed a nested, cord-like, cribriform distribution, polygonal cells, uniform size, and lack of cytoplasm. Tumor cell nuclei were large and round, with clear nuclear membranes, fine and scattered chromatin, absence of nucleoli, and mitotic figures of 10 per 50 high power fields. Among them, one patient had sarcoma and squamous cell carcinoma in situ, one patient had squamous cell carcinoma in situ, and one patient had unique cell morphology. Immunohistochemical staining showed that all cancer cells expressed CKpan, synaptophysin and CD56. There were seven cases with perinuclear dot-like positivity of CK20. Six MCCs expressed chromogranin A to varying degrees, while 2 MCCs were weakly positive for p63. The nuclear positive index in the Ki-67 hotspot area was 60%.Conclusion:The histology of MCC varies. Rendering a correct diagnosis of MCC requires adequate sampling, close correlation with clinical history and rational use of immunohistochemical staining. The treatment requires standardized surgery, postoperative radiotherapy and multimodal chemotherapy. Immunotherapy may replace the traditional treatment in the future.

【Objective】 To analyze the correlation between the expressions of ZEB1, androgen receptor (AR), E-cadherin (E-Ca), N-cadherin (N-Ca) and clinicopathological features of prostate cancer patients with different risk levels, and to explore their significance. 【Methods】 The clinical data of 47 patients with prostate cancer treated during Nov.2013 and Jun.2021 were retrospectively analzyed. The patients were divided into medium-low risk group and high-risk group. The expressions of ZEB1, AR, E-Ca and N-Ca in the prostate cancer tissues of the two groups were detected with immunohistochemical staining. The relationship between the expressions and Gleason grade, prostate-specific antigen (PSA) level and TNM stage was analyzed. 【Results】 The positive expression rate of ZEB1 increased with higher risk, Gleason score, and PSA level (P<0.01); the strong positive expression rate of AR decreased with higher risk and Gleason score (P<0.05); the positive expression rate of E-Ca decreased with increased risk, Gleason score, and PSA level (P<0.05); the positive expression rate of N-Ca increased with the increased risk and Gleason score (P<0.01); the positive expression rate of ZEB1 increased with higher tumor stage and TNM stage (all P<0.01); the strong positive expression rate of AR decreased only with increased TNM stage (P<0.05). Patients whose first surgical specimen showing a higher expression level of ZEB1 were more likely to develop into castration-resistant prostate cancer CRPC (P<0.05). 【Conclusion】 ZEB1 and N-Ca levels increase with increased tumor aggressiveness, while AR and E-Ca levels decrease. ZEB1, AR, E-Ca and N-Ca play important roles in prostate cancer progression. ZEB1 can not only affect prostate cancer through epithelial stromal transformation (EMT), but also through AR. ZEB1 may also be related to the development of CRPC.