Fibrosarcoma of the foot masquerading as plantar fasciitis.

Fibrosarcoma is an uncommon, malignant soft-tissue tumor that is rarely found as a primary neoplasm in the foot. A case report is presented that demonstrates a large, locally invasive fibrosarcoma of the plantar aspect of the foot with initial symptoms consistent with plantar fasciitis. Below-the-knee amputation was performed as curative treatment.