Diagnostics
Mixed Epithelial Stromal Tumour of the Seminal Vesicle Presenting with Recurrent Acute Urinary Retention: A Case Report
By Daniel Vas, A Iacono, Tarek Ajami and 5 others.
Abstract
Background
Mixed epithelial stromal tumour (MEST) is a rare biphasic neoplasm, most commonly arising in the kidney. Seminal vesicle involvement is exceedingly uncommon, and its clinical and imaging characteristics remain poorly defined. We present a rare case with detailed clinical and urological evaluation, multiparametric MRI characterisation, and radiologic-pathologic correlation.
Case presentation
A 34-year-old man presented with recurrent acute urinary retention requiring repeated catheterization and, subsequently, an indwelling urinary catheter. Urological evaluation, including ultrasonography and cystoscopy, demonstrated marked mass effect on the bladder and prostatic urethra without an intravesical lesion. Contrast-enhanced CT and MRI revealed a large retrovesical mass arising from the right seminal vesicle, measuring approximately 11.5 × 9 × 10.5 cm. MRI demonstrated a predominantly multiloculated cystic lesion containing haemorrhagic or proteinaceous material, with an enhancing papillary solid component showing mild diffusion restriction and progressive enhancement. The lesion produced marked mass effect on the bladder, prostate, and rectum, without local invasion. Robotic-assisted resection of the right seminal vesicle was performed. Histopathology demonstrated a biphasic epithelial and stromal proliferation without atypia, necrosis, or increased mitotic activity, consistent with MEST.