Giant malignant peripheral nerve sheath tumor of the scalp.

PURPOSE Malignant peripheral nerve sheath tumors (MPNST) constitute a group of soft tissue neoplasms with neurogenic origin. Association of MPNST with neurofibromatosis type 1 (NF1) has been frequently reported as a result of malignant transformation of a pre-existing plexiform neurofibroma. However, most of the cases are small and few have been described with giant dimensions. We describe a case of a giant MPNST in an unusual location (scalp), in a NF1 patient. CASE REPORT A fifty-six years old woman with a history of NF1 since childhood was admitted due to a rapid growing of a scalp tumor in occipital region. The mass had 15 cm in the largest dimension and a central ulceration with purulent secretion. Computed tomography revealed no bone invasion. The tumor was surgically removed and the histopathological examination revealed a neurofibrosarcoma. The patient had a good post operatory evolution and notwithstanding the tumor size, no metastasis was found and she was discharged to oncologic follow-up. CONCLUSION Given the poor prognosis of MPNST, patients with NF1 should be aware that neurofibromas can undergo malignant transformation and report signs such as rapid growth of a pre-existing lesion.