Abstract
Squamous differentiation in prostate cancer is rare, presenting unique diagnostic and therapeutic challenges. We report a case of high-grade prostatic adenocarcinoma with focal squamous differentiation in a 73-year-old man without prior radiation or androgen deprivation. Immunohistochemistry confirmed the squamous component arose from the adenocarcinoma, not a separate malignancy. This case highlights the importance of morphological assessment and strategic immunohistochemical evaluation to distinguish prostate cancer variants. A biopsy capturing only the squamous component could have led to misdiagnosis and inappropriate treatment. To improve diagnostic accuracy and management, we propose the term 'adenocarcinoma with focal squamous differentiation' over adenosquamous carcinoma.