Primary adenoid cystic carcinoma (basal cell type) of the prostate: a case report

Prostatic adenoid cystic (basal cell) carcinoma is an extremely rare malignant epithelial neoplasm, accounting for a very low proportion of all prostate malignancies. Its clinical symptoms and imaging features are non-specific, and serum PSA levels are mostly normal or only mildly elevated, posing diagnostic challenges.

A 46-year-old male presented with progressive hematuria and lower urinary tract obstruction symptoms. His PSA level was not significantly elevated. Imaging revealed a prostatic space-occupying lesion with multiple adjacent small lymph nodes. Histopathological examination of biopsy specimens showed tumor cells arranged in solid nests and cribriform patterns, with hyperchromatic nuclei, uniform morphology, and peripheral palisading. Immunohistochemistry showed positivity for p63 and high-molecular-weight CK, negativity for PSA, and a Ki-67 index of approximately 40%. A diagnosis of primary adenoid cystic (basal cell) carcinoma of the prostate was confirmed.

This case highlights the importance of recognizing this rare tumor in patients with prostatic mass and normal PSA, with diagnosis relying on characteristic histomorphology and immunophenotype.