Histomorphological study of prostatic adenocarcinoma and its mimics

Prostate adenocarcinoma (PC) is one of the common cancers in India and world over. Numerous prostatic, nonprostatic lesions, and normal structures can be very similar to adenocarcinoma. A pathologist's awareness of the benign mimics is important for the diagnosis of PC.

The aim of this study was to determine the prevalence, clinical, and histopathological features of PC, and its common mimics, and to study the criteria for their distinction from PC.

A prospective study of histopathological features of radical prostatectomy and transurethral resection of the prostate specimens, sent to the department of pathology in a medical college, for a period of 2 years was done. A brief clinical history followed by a clinical examination, including per-rectal findings and serum prostate-specific antigen (PSA) levels, was noted.

After excluding all the cases of benign hyperplasia of prostate without any associated findings, 50 cases of operated surgical specimens of prostate were studied. PC was the most frequent diagnosis in 28 patients of 50 cases (56.0%). Basal cell hyperplasia formed the predominant mimic (26.0%), followed by prostatic intraepithelial neoplasia (8%), prostate atrophy (4%), clear-cell cribriform hyperplasia(4%),, and one case of atypical adenomatous hyperplasia (2%). Serum PSA was >4 ng/mL in all the cases of PC. In three of the mimics, PSA was >4 ng/mL and in the rest it was <4 ng/mL. Immunohistochemistry (IHC) was not applied in our study.

Biopsy still remains a gold standard for diagnosis of PC and its mimics. All the lesions in the above study were diagnosed on routine hematoxylin and eosin staining. IHC is useful especially for lesions in the grey zone but not in routine histopathological study and should not be used as a screening test but should be applied in specific selected cases only.