Undifferentiated Pleomorphic Sarcoma of the Prostate, a Rare Cause of Genitourinary Tumour in Men.

Background: Undifferentiated pleomorphic sarcoma (UPS) of the prostate is an extremely rare and malignant tumour, accounting for only 0.1%-0.24% of all prostate neoplasms. Reclassified as a malignant fibrous histiocytoma by the World Health Organization in 2002, UPS predominantly affects men aged 50-70 years. Diagnosis is difficult due to nonspecific symptoms, such as acute urinary retention (AUR) and haematuria, along with normal prostate-specific antigen levels, which often lead to confusion with benign prostatic hyperplasia.

Methods: This case report discusses the clinical presentation, diagnostic process and management of an 82-year-old man who presented with AUR. Imaging studies, such as transrectal ultrasound, computed tomography and magnetic resonance imaging, were used to evaluate the tumour. Histological examination and immunostaining were performed after transurethral resection to confirm the diagnosis of UPS.

Results: The images revealed a large, irregular, invasive tumour within the prostate, leading to a radical cystoprostatectomy. Histological analysis showed atypical spindle cells and positive immunostaining for histiocytic markers, such as vimentin and CD68 (a marker of monocyte/macrophage lineage), confirming the diagnosis of UPS. Surgical margins were negative, and no residual disease was detected in the postoperative period.

Conclusions: The rarity of prostatic UPS underscores the ongoing debate about its optimal management. This case contributes to the limited literature on prostatic UPS, highlighting the importance of early detection and complete surgical removal to improve prognosis. More research is needed to establish a consensus on adjuvant therapies.