Malignant peripheral nerve sheath tumor of the penis: a case report and review of the literature.

Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft tissue sarcomas that arise from peripheral nerve fibers and are derived from Schwann cells, perineural cells, or fibroblasts. MPNST is an aggressive neoplasm in which local recurrence is common and complete excision of the mass should be the goal of surgery. We report a case of MPNST involving the penis in a 14-month-old boy. This is only the second reported case of penile MPNST without evidence of neurofibromatosis 1 and the first of which to occur in a patient this young.