Smooth Muscle Tumor of Uncertain Malignant Potential of the Urinary Bladder: A Case Report and Review of the Literature.

Smooth muscle tumors of uncertain malignant potential (STUMPs) are uncommon neoplasms arising from smooth muscle cells, with no de fi nite and clear benign or malignant features after histologic evaluation. 1 These tumors reveal “ intermediate ” bio- logical features in many cases; aggressive local behavior has been widely described, but with low to moderate propensity to metas- tasize. Most STUMPs have been described in gynecological case series, and most of these smooth muscle tumors are of uterine origin. 2-4 The clinical management of STUMP is still controver- sial, because little is known about the natural history of these tumors, and no convincing correlations between pathological fea- tures and oncological outcomes have been reported. In this report, we describe an interesting case in a healthy young patient, of rapidly growing, locally aggressive bladder STUMP that was treated using surgical excision