Superficial malignant peripheral nerve sheath tumor from recurrent neurofibroma in the abdominal wall of a patient without neurofibromatosis type 1

Malignant peripheral nerve sheath tumor (MPNST) is rare, accounting for 5-10% of all soft tissue sarcomas. MPNST is characteristically aggressive and has a poor prognosis. Fifty percent of patients with MPNST have neurofibromatosis type 1 (NF1). NF-associated MPNST occurs more often at younger ages than sporadic MPNST, but the survival difference is controversial. Superficial MPNST from a recurrent neurofibroma is extremely rare and only a limited number of cases have been reported in the literature. Herein, we report an unusual case of superficial MPNST from a recurrent neurofibroma in a patient without NF1.