Intracranial melanotic schwannoma: a case report of recurrence with extra- and intradural manifestation two decades after initial diagnosis and treatment.

Abstract

Introduction & Melanotic schwannoma (MS) is a very rare nerve sheath tumor characterized by melanin-producing cells that display ultrastructural features of Schwann cells [24] . This type of tumor was fi rst described in 1932 [17] and occurs primarily in the paraspinal region, originating from the spinal nerve roots or sympathetic ganglia. Craniofacial or intracranial locations are rare [15, 21] . However, extraneural locations such as skin, soft tissues, bone and viscera have also been described [5, 7] . In a minority of cases, MS may have multiple nodules [6, 26] . Although MS have been considered to be slow-growing, benign tumors, prognosis can be poor as a result of local recurrence or malignant progression [9] . 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 [2] . 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 [15, 18] .