Giant seminal vesicle cystadenoma diagnosed on imagery after acute urinary retention in a middle-aged man: A case report with brief literature review.

Seminal vesicle cystadenomas (SVC) are exceedingly rare benign tumors, with only 22 cases reported in the literature up to 2018. Here, we present the case of a 40-year-old man who presented with acute urinary retention secondary to a giant pelvic mass. Radiological imaging diagnosed a retrovesical well-delimited multicystic tumor, initially suspected to arise from the left lobe of the prostate but ultimately confirmed to originate from left seminal vesicle. Despite inconclusive biopsy results and normal tumor markers, surgical removal was recommended to confirm diagnosis. The patient initially opted for conservative management but eventually underwent open surgery due to the tumor's significant enlargement on the follow-up imagery. The procedure, though challenging due to the mass's size and proximity to adjacent structures, was successfully completed with minimal blood loss and uncomplicated postoperative phase. Histopathological evaluation confirmed the diagnosis of SVC, marking the largest reported case of its kind and the first to be discovered upon investigation of an acute urinary retention. This case highlights importance of considering SVC in the differential diagnosis of pelvic masses and underscores the role of imagery and surgery together for definitive diagnosis.