Primary prostatic extra-gastrointestinal stromal tumor causing giant prostatomegaly.

Prostatic extra-gastrointestinal stromal tumors (E-GIST) are rare mesenchymal tumors with only 9-cases reported in the English literature so far. We herein describe a case of E-GIST causing massive enlargement of the prostate gland. A 55-year-old male was diagnosed with localized prostatic E-GIST causing massive prostatomegaly (1230 cc) during workup for lower urinary tract symptoms (LUTS). The patient was managed with Imatinib mesylate therapy as high anesthetic risks precluded surgery. Given the rarity, E-GISTs should be included in the differential diagnosis of patients presenting with LUTS as it may influence the treatment decisions.