Primary squamous cell carcinoma of the prostate with coexisting separate adenocarcinoma: A case report and review of the literature.

Primary squamous cell carcinoma (PSCC) of the prostate is a rare, aggressive malignancy that presents diagnostic and therapeutic challenges. We present a unique case of PSCC arising from squamous metaplasia coexisting with a separate adenocarcinoma, forming a collision tumor. Dual-tracer imaging demonstrated distinct FDG and PSMA-avid metastases, reflecting independent biology. This case represents, to our knowledge, the first report of a true prostatic collision tumor with independent PSCC and adenocarcinoma, expanding the spectrum of prostate cancer variants.