Uterine smooth muscle tumors of uncertain malignant potential: diagnostic challenges and therapeutic dilemmas. Report of 2 cases and review of the literature.

Morphologically, there exist variants of uterine smooth muscle tumors that cannot be clearly interpreted and classified as benign or malignant. Because their behavior and clinical prognosis is also uncertain, the World Health Organization has termed these "smooth muscle tumors of uncertain malignant potential" (STUMP). Herein we describe 2 cases, present a review of the literature, and highlight the diagnostic challenges and therapeutic dilemmas associated with uterine STUMP in myomectomy specimens from women who wish to maintain or enhance their fertility. The clinical course of residual STUMP remains speculative.