Metatarsal stress fractures secondary to soft-tissue osteochondroma in the foot: case report and literature review.

Soft-tissue osteochondromas are rare, benign tumours developing in the soft tissues. Diagnosis is challenging however, as the differential includes malignancy. As simple excision is curative, early recognition by clinical and radiological evaluation will help avoid unnecessary surgery. A 43-year-old gentleman presented to us with a painful lump on the plantar aspect of his foot. Initial imaging suggested bony involvement of the lesion, raising concerns of malignancy. Further investigation demonstrated the bony abnormalities to be stress fractures, caused by altered forces due to the lump. The lump was excised and histologically confirmed to be a soft-tissue osteochondroma. Soft-tissue osteochondromas have not previously been reported in association with stress fractures. We present this case, a literature review and a list of differential diagnoses highlighting the importance of considering soft-tissue osteochondroma when evaluating a well-defined, osseous, soft-tissue mass in the extremity, and the difficulties in making this diagnosis.