title: Intracranial intermediate-grade meningeal melanocytoma with increased cellular proliferative index: an illustrative case associated with a nevus of Ota.
abstract: Solitary primary melanocytic tumors of the central nervous system (CNS) represent a spectrum of lesions ranging from well-differentiated melanocytoma to melanoma. The association of a meningeal melanocytoma with an ipsilateral nevus of Ota is extremely rare, with only six cases reported in the literature to date. Only a minority of melanocytic tumors correspond to lesions of intermediate-grade malignancy, whose biological behavior and outcome remain undetermined. We report a new case of a 25-year-old man with a giant fronto-temporal intracranial meningeal melanocytoma associated with a congenital nevus of Ota, who suffered an acute neurological deterioration requiring an emergent surgical procedure. Despite total removal of the lesion, the patient did not recover from the operation due to a malignant infarct of the right hemisphere. The lesion showed no histological criteria of malignancy but did exhibit an elevated (8%) MIB-1/Ki-67 cell proliferative index, which suggested an intermediate-grade melanocytoma. In addition, its metabolic profile, determined by in vivo proton magnetic resonance spectroscopy (MRS), was similar to that observed in most high-grade gliomas. To our knowledge, this is the first case of a meningeal melanocytoma of intermediate grade associated with a nevus of Ota reported in the literature. Only two additional intermediate-grade melanocytomas showing an elevated MIB-1/Ki-67 labeling index have been previously reported. The MIB-1/Ki-67 labeling index may have potential prognostic value in helping the clinician to predict an aggressive clinical behavior and/or malignant progression for primary melanocytic neoplasms of the CNS.
authors.affiliation: Department of Neurosurgery, La Princesa University Hospital, C/Diego de León 62, 28006, Madrid, Spain. m_navas_garcia@hotmail.com.
authors.forename: Marta
authors.initials: M
authors.lastname: Navas
authors.affiliation: Department of Neurosurgery, La Princesa University Hospital, C/Diego de León 62, 28006, Madrid, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Pascual
authors.affiliation: Department of Pathology, La Princesa University Hospital, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Fraga
authors.affiliation: Department of Neurosurgery, La Princesa University Hospital, C/Diego de León 62, 28006, Madrid, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Pedrosa
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Sophia
authors.initials: S
authors.lastname: Shakur
authors.affiliation: Department of Neurosurgery, La Princesa University Hospital, C/Diego de León 62, 28006, Madrid, Spain.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Carrasco
authors.affiliation: Department of Neurosurgery, La Princesa University Hospital, C/Diego de León 62, 28006, Madrid, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Martínez
authors.affiliation: Department of Neuroradiology, La Princesa University Hospital, Madrid, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Manzanares
authors.affiliation: Department of Neurosurgery, La Princesa University Hospital, C/Diego de León 62, 28006, Madrid, Spain.
authors.forename: Rafael García
authors.initials: RG
authors.lastname: de Sola
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D009507:Nevus of Ota / Q000473:pathology*; D009508:Nevus, Pigmented / Q000601:surgery; D011859:Radiography; D015898:Tomography Scanners, X-Ray Computed