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

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNST) 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 tumors. Some authors suggest adjuvant radiotherapy for local tumor control, however there is uncertainty about its advantages and its use is not without risks. CASE DESCRIPTION: We present the case of a 31-year-old male who presented with a large necrotic scalp tumor of the left fronto-parietal convexity. MRI 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 reconstructerd with a Latissimus Dorsi Muscle free flap. The anatomopathological diagnosis was MPNST. Then he underwent adjuvant radiotherapy. After seven months patient developed a progressive right hemiparesis and MRI showed results compatible with cerebral radiation necrosis. This motor deficit improved with corticotherapy. After nine months the patient went back to his home country and 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.