title: Undifferentiated carcinoma of the prostate with small cell features: immunohistochemical subtyping and reflections on histogenesis.
abstract: To investigate the histogenesis of undifferentiated carcinoma of the prostate with small cell features we analysed the expression of neuroendocrine (NE) markers, the androgen receptor (AR), and prostate-specific antigen (PSA) in 19 undifferentiated carcinomas of the prostate. The proliferative activity (MIB-1/Ki67) of the tumours was examined, and the clinical data reviewed. The results identified two groups: carcinomas in group 1 were positive for PSA and AR and negative for NE markers. The mean MIB-1 labelling index (LI) was 34.8% and the mean serum PSA value 56.4 ng/ml. Two of the 7 patients died within 12 months after tumour diagnosis. The tumours in group 2 were NE differentiated small cell carcinomas (SCC), which were negative for PSA and AR. The mean MIB-1 LI was 82.6% and the mean serum PSA value 7.1 ng/ml. Seven of the 10 patients died between 2 and 12 months after tumour diagnosis. Positive staining for NE markers in combination with negative staining for PSA and AR and a high MIB-1 LI substantiated the diagnosis of a NE-SCC. We suggest that this tumour has a stem cell origin and does not derive from a dedifferentiated adenocarcinoma or from benign NE cells of the prostatic epithelium. This clear distinction of NE-SCC from NE-negative undifferentiated carcinoma is in accordance with the differing biological behaviour and response to therapy of the two tumour entities.
authors.affiliation: Department of Pathology, Hegau-Klinikum, Singen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Helpap
authors.forename: J
authors.initials: J
authors.lastname: Köllermann
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000145:classification* / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D018288:Carcinoma, Small Cell / Q000737:chemistry / Q000145:classification* / Q000473:pathology*; D002454:Cell Differentiation; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010751:Phosphopyruvate Hydratase / Q000032:analysis; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000145:classification* / Q000473:pathology*; D013194:Staining and Labeling; D016708:Synaptophysin / Q000032:analysis
chemical_list: D053379:Chromogranin A; D002864:Chromogranins; D016708:Synaptophysin; D010751:Phosphopyruvate Hydratase