Deep Soft Tissue Leiomyoma Mimicking Fibromatosis in a 5-year-old Male

Leiomyomas of the deep soft tissue in the extremities of children are very rare. These benign soft tissue tumors occur more frequently in adults between the fourth and sixth decades of age. Women are more commonly affected than men, with the uterus the most common location. We present a rare case of deep soft tissue leiomyoma in the foot of a 5-year-old male. The tumor was misdiagnosed as a desmoid-type fibromatosis from the findings of both magnetic resonance imaging and needle biopsy. The unusual age of presentation, atypical location, and failure of magnetic resonance imaging and ultrasound-guided needle biopsy in diagnosing the lesion make the case interesting. The case also highlights the importance of treating such patients at specialist tertiary centers with a multidisciplinary setting.