Extra-gastrointestinal stromal tumor arising in the prostate: an unusual anatomical location

Gastrointestinal stromal tumors (GISTs) are tumors of mesenchymal origin arising from the walls of the gastrointestinal (GI) tract, with stomach being the most common site followed by the small intestine. Those with similar morphology identified outside the GI tract are termed extra-gastrointestinal stromal tumors and are often located in the mesentery, omentum, pelvis, retro-peritoneum, rectovaginal septum, perivaginal soft-tissue, and very rarely the prostate. Due to their malignant potential, it is utmost essential to diagnose such extra-intestinal occurrences, with immunochemistry being an effective tool in its diagnosis. We herein report a case of GIST of the prostrate in a 75-year-old male presenting with dysuria and urinary retention and discuss the role of immunohistochemistry markers that aid in diagnosis and its differentiation from other malignant conditions involving the prostrate. This case serves best to promote awareness of GIST in unusual anatomical locations to help early diagnosis and prompt subsequent management.