Multifocal vulvar smooth muscle tumor with an unusual intravascular growth pattern and multiple local recurrences in a 10-year-old child: a diagnostic dilemma.

Smooth muscle tumors of the vulva are rare entities with variable morphologic features and clinical behavior. Our report summarizes the case of a multifocal vulvar smooth muscle tumor of undetermined malignant potential with an unusual intravascular growth pattern and subsequent local recurrence in a 10-year-old girl, the youngest case reported to date, and reviews the specific pathologic findings of that category. Vulvar smooth muscle tumors of undetermined malignant potential represent a diagnostic, prognostic, and therapeutic challenge. The histologic features of this case were predictive of local recurrence, although the significance of the intravascular growth pattern is still uncertain. The relationship of this multifocal, recurrent tumor to the clinical entity, vulvar leiomyomatosis, is unknown at this time.