Anterior mediastinal desmoid tumor with CT and MR imaging.

Desmoid tumors, or aggressive fibromatoses, are rare, histologically benign tumors with biologic behavior that is intermediate between benign fibrous proliferations and low-grade fibrosarcoma. These tumors can cause significant morbidity and mortality by their propensity for local invasion and recurrence following surgical excision. A case of an anterior mediastinal desmoid tumor in a 67-year-old woman is reported with computed tomography and magnetic resonance imaging findings.