Intracranial Melanotic Schwannoma: A Case Report of Recurrence with Extra- and Intradural Manifestation Two Decades After Initial Diagnosis and Treatment
22 April 2010 (eFirst)
Melanotic schwannoma (MS) is a very rare nerve sheath tumor characterized by melanin-producing cells that display ultrastructural features of Schwann cells . This type of tumor was first described in 1932  and occurs primarily in the paraspinal region, originating from the spinal nerve roots or sympathetic ganglia. Craniofacial or intracranial locations are rare  . However, extraneural locations such as skin, soft tissues, bone and viscera have also been described  . In a minority of cases, MS may have multiple nodules  . Although MS have been considered to be slow-growing, benign tumors, prognosis can be poor as a result of local recurrence or malignant progression . Melanotic schwannoma occurs in relatively young adults (mean age 35 years) and have no sex predilection. Epidemically, two types of tumors can be distinguished: the sporadic variant and psammomatous melanotic schwannoma associated with the Carney complex, a rare, autosomal dominant hereditary syndrome characterized by variegated skin pigmentation, cardiac myxomas, endocrine overactivity, and nerve sheath tumors . Psammoma bodies are present in more than 50% of MS. Immunohistochemistry reveals that S100, HMB-45 and vimentin are strongly expressed by most cells in MS  .