Giant Malignant Peripheral Nerve Sheath Tumor of the Scalp: Case Report and Review of the Literature.

Background: Malignant peripheral nerve sheath tumors (MPNSTs) are rare nervous system tumors that rarely appear on the scalp. About half of the scalp MPNSTs described in the literature have reached giant dimensions at the time of diagnosis. The surgical treatment is the gold standard for this type of tumor. Some authors suggest adjuvant radiotherapy for local tumor control, although there is uncertainty about its advantages and its use is not without risks.

Case Description: We present the case of a 31-year-old man who presented with a large necrotic scalp tumor of the left frontoparietal convexity. magnetic resonance imaging showed a large extra-axial tumor, measuring 17 x 17 x 8 cm, centered on the soft tissues, with skull erosion and signs of dural invasion, although with no intradural component. The tumor was surgically removed and the osteocutaneous defect was reconstructed with a latissimus dorsi muscle free flap. The anatomopathologic diagnosis was MPNST. The patient then underwent adjuvant radiotherapy. After 7 months he developed a progressive right hemiparesis and magnetic resonance imaging showed results compatible with cerebral radiation necrosis. This motor deficit improved with corticotherapy. After 9 months the patient went back to his home country and was subsequently lost to follow-up.

Conclusions: Giant MPNSTs of the scalp are highly aggressive lesions that should primarily be treated in a surgical fashion. Although adjuvant radiotherapy has been used routinely for local tumor control, there is uncertainty about its advantages.