A Rare Case of Aggressive Melanotic Schwannoma Occurred in Spinal Nerve of a 59-Year-Old Male

Melanotic schwannoma (MS) is a rare variant of nerve sheath neoplasm that shows ultrastructural and immunophenotypical features of Schwann cells but also has cytoplasmic melanosomes and is reactive for melanocytic markers as well. Unlike conventional schwannoma, which is totally benign, MS has an unpredictable prognosis and is thought to have low-malignant potential. Herein, we present a rare case of recurrent MS in lumbar spine of a 59-year-old male.

Psammomatous melanotic schwannoma as a component of Carney complex.

Melanotic schwannoma is a rare form of pigmented neural tumor commonly arising from the posterior spinal nerves and ganglia. Two variants have been described, psammomatous and nonpsammomatous. 50% of psammomatous tumors are associated with Carney complex. The biologic behavior of the tumor is diffi cult to predict and slightly over 10% of the tumors follow malignant course. We present a case of psammomatous melanotic schwannoma as part of Carney complex in a 67-year-old male. Clinical examination revealed oral mucosal and abdominal skin pigmentation. Magnetic resonance imaging showed an intradural extramedullary lesion at D8-D12 level. Intraoperative squash smear study showed sheets of spindle cells with abundant intracytoplasmic melanin pigmentation and few psammoma bodies. Based on clinical, radiologic, and histopathological fi ndings with immunohistochemistry correlation a fi nal diagnosis of psammomatous melanotic schwannoma was rendered.

Schwannoma melanótico: reporte de un caso y revisión de la literatura / Melanotic schwannoma: a case report and literature review

Schwannomas are benign neoplastic lesions which originate from Schwann cells. A rare variant is the melanotic schwannoma. Accurate discrimination of this entity may be difficult due to differential diagnosis with malignant tumors, especially with metastatic melanoma, which has a potential ominous prognosis and a radically different treatment. We report the case of a 60-year-old woman with neurological sensorimotor involvement, presenting progressive caudo-cranial involvement more pronounced on the right side. MRI showed an intradural extramedullary mass with hyperintense signal intensity on T1 and T2 images, whereas no significant increase in signal intensity of the spinal cord was observed. Tumor was resected and sent for anatomopathological analysis which revealed a non-psammomatous melanotic schwannoma.

Los schwannomas son lesiones neoplásicas benignas derivadas de las células de Schwann. Una variante poco frecuente es el schwannoma melanótico. El diagnóstico de esta entidad reviste complejidad debido al diagnóstico diferencial con tumores malignos, especialmente el melanoma metastásico, teniendo este último un potencial pronóstico ominoso y un tratamiento radicalmente distinto. Se realizó una revisión de literatura en relación a un caso clínico de una mujer de 60 años con compromiso neurológico de tipo sensitivo-motor, progresivo caudo-craneal mayor a derecha. La RM demostró una masa intradural extramedular, con hiperintensidad en secuencias T1 e hiposeñal en T2, sin aumento de señal significativo de la médula espinal. El tumor fue resecado revelando en el estudio anatomopatológico un schwannoma melanótico, no psammomatoso. En relación al caso clínico, pudimos observar la importancia del estudio imaginológico con RM y su confirmación anatomopatológica. Recalcamos además, la necesidad del seguimiento a largo plazo.

Melanotic Acoustic Schwannoma

Melanotic Schwannoma arising from the acoustic nerve is extremely rare and only three cases have been reported. We report an additional case of melanotic schwannoma occuring at the left cerebellopontine angle in a 53-year-old man presented with left facial numbness and tinnitus. After surgical removal of the mass, there has been no evidence of recurrence for 13 months.

Histogenesis,differential diagnosis and prognosis of melanotic schowannoma / 中国癌症杂志

Purpose:To study the histogenesis,the differential diagnosis and the prognosis of melanotic schwannoma.Methods:The age of the patients was 4,17,28 years old, respectively.Three cases of melanotic schwannoma were examined using histologic (HE), immunohistochemical (ABC method) and electron microscopic techniques. Results: The diameter of tumor was 2,4,8, respectively. Histological examination showed pigmented spindle cells arranged in interlacing fascicles and occasional nuclear palisading. The pigmented polygonal cells were loosely arranged in sheets. After bleaching, the nuclei were oval and some showed slight pleomoprohism with prominent nucleoli, and nuclear mitoses were found. There was local invasion in two cases. Immunohistochemical stains for S 100 protein, HMB45, Vim, Leu 7, NSE were positive. Ultrastructrual examinations showed a lot of melanosomes in all stages of development and seldom basal lamina. Conclusions:①Melanotic schwannoma usually occurs in young adults. Most of the tumors are benign or only potentially malignant. Malignant MS is rare,and require follow up. ②MS originate from neural crest with a proliferation of the bipotential cell.

Melanotic Schwannoma in Cervical Spine: A Case Report

Primary melanotic schwannoma in spinal cord is a very uncommon disorder, eight cases of melanotic schwannoma in spinal cord have been found in the literature. We present a case report of a patient with an intradural, extramadullary melanotic schwannoma in cervical spine and the literature on melanotic schwannoma is reviewed. The proposed theories on the origin of these tumors and treatment are discussed.

Pigmented(melanotic) Schwannoma of the Cervical Spinal Canal: A case report

Pigmented(melanotic) schwannoma is a very rare variant of schwannoma that characteristically has massive cytoplasmic melanin. Since it was described in 1946 by Bjorneboe, about 44 cases have been reported in the English literature. It has a relatively benign clinical course, but the cases arising in the cranial nerve and sympathetic chain show aggressive behavior with malignant potential. We herein report a typical case of pigmented schwannoma with light microscopic findings. The results of immunohistochemical and electronmicroscopic study are also presented. The patient was a 30 year-old Korean male who had a mass in his posterior neck for 10 years that recently.began to induce neurologic manifestations. The tumor, which was mainly in the extramedullary intradural space of the cervical canal extending to the extradural space and soft tissues of the neck, was relatively well defined and composed of black solid tissue. Microscopic, densely pigmented spindle cells forming fascicles, nuclear palisading, whorling and polygonal cells with vacuolated or clear cytoplasm were characteristic. Immunohistochemically, the tumor cells were positive for vimentin, S-100 protein, and HMB-45. Electron microscopic study revealed that the tumor cells have interdigitating cytoplasmic processes containing varying stages of melanosomes with a very focal basal lamina and Luse body like collagen bundles.