L-tryptophan-induced eosinophilia-myalgia syndrome associated with primary cutaneous malignant fibrous histiocytoma and extraabdominal desmoid tumor.

A 57-year-old woman with L-tryptophan-induced eosinophilia-myalgia syndrome, 23 months after the onset of symptoms, experienced development of a parasternal malignant fibrous histiocytoma on previously scleroderma-like skin areas and, almost concurrently, an extraabdominal desmoid tumor of the left arm muscle fascia. The malignant fibrous histiocytoma was treated by surgical excision without sign of recurrence or metastasis 19 months later. Radiation therapy was performed on the extraabdominal desmoid tumor. We suspect that these two connective tissue tumors in this patient were related to the exposure to contaminated L-tryptophan, which interfered with connective tissue metabolism.