Myxoid malignant fibrous histiocytoma mimicking papular mucinosis.

Malignant fibrous histiocytoma is the most common type of soft tissue sarcoma in late adulthood. The myxoid variant of malignant fibrous histiocytoma, also known as myxofibrosarcoma, can develop in subcutaneous rather than deep soft tissue, and the true extent of these superficial tumors is often underestimated. Patients with these low-grade myxoid malignant fibrous histiocytomas have an excellent 5-year survival rate, and it is therefore important to recognize them. We present a case with a superficial cutaneous accumulation of mucin that was diagnosed clinically and histologically as papular mucinosis. In retrospect, a subcutaneous presentation of myxofibrosarcoma should have been considered.