[Pseudohyperplastic carcinoma with xanthomatous changes: a neoplasm mimicking glandular hyperplasia of the prostate]

Varieties of prostatic adenocarcinoma whose architectural and cytological appearance mimicked benign lesions have been reported in recent decades. Such neoplasms include xanthomatous (foamy) carcinoma and pseudohyperplastic carcinoma. We recently studied five carcinomas showing a cytoarchitectural combination of both neoplasms which were confused with benign glandular proliferations.

Five cases (1.8%) of pseudohyperplastic carcinoma showing xanthomatous changes were selected from a total of 280 biopsies showing prostate carcinoma. Glandular prostatic hyperplasia was originally diagnosed in four of such cases.

Patient age ranged from 54 and 78 years (mean, 64 years). All patients had high prostate-specific antigen levels, and digital rectal examination showed abnormalities in four of them. Neoplasms showed minimal atypia and consisted of mid- to large-sized glands arranged in nests resembling hyperplastic nodules. Glands showed papillary projections, infoldings, and undulations. Most nuclei were basal, small and hyperchromatic, and nucleomegaly was only seen in two biopsies in isolated histological fields. Several useful criteria for diagnosis of acinar carcinoma, such as perineural infiltration, mitosis, crystalloids, blue secretions, and prostatic intraepithelial neoplasm, were absent.

Prostatic carcinoma with a pseudohyperplastic pattern and xanthomatous changes mimics hyperplastic glands. Timely detection is critical to avoid treatment delay.