BACKGROUND A malignant melanotic nerve sheath tumor(MMNST),previously known as a melanotic schwannoma,is a rare variant of a peripheral nerve sheath tumor composed of Schwann cells with melanotic differentiation.Only ...BACKGROUND A malignant melanotic nerve sheath tumor(MMNST),previously known as a melanotic schwannoma,is a rare variant of a peripheral nerve sheath tumor composed of Schwann cells with melanotic differentiation.Only a few reports of spinal MMNST have been reported.CASE SUMMARY In the first case,a 58-year-old woman presented with a history of low back pain and paresthesia.Magnetic resonance imaging(MRI)and computed tomography(CT)of the lumbar spine revealed an intradural extramedullary mass lesion with amorphous linear calcification.Complete tumor resection was performed and histological examination revealed a psammomatous melanotic schwannoma.In the second case,a 72-year-old man presented with low back pain and paresthesia.MRI of the thoracolumbar spine revealed an intramedullary mass lesion at the T11 vertebral body level.The mass lesion was hypointense on T2WI and hyperintense on T1WI.Tumor resection was performed and the histologic result was melanotic schwannoma.CONCLUSION MMNST should be considered in the differential diagnosis when calcification or melanin is seen in an intradural spinal tumor.展开更多
基金Supported by a Clinical Research Grant from Pusan National University Hospital(2020).
文摘BACKGROUND A malignant melanotic nerve sheath tumor(MMNST),previously known as a melanotic schwannoma,is a rare variant of a peripheral nerve sheath tumor composed of Schwann cells with melanotic differentiation.Only a few reports of spinal MMNST have been reported.CASE SUMMARY In the first case,a 58-year-old woman presented with a history of low back pain and paresthesia.Magnetic resonance imaging(MRI)and computed tomography(CT)of the lumbar spine revealed an intradural extramedullary mass lesion with amorphous linear calcification.Complete tumor resection was performed and histological examination revealed a psammomatous melanotic schwannoma.In the second case,a 72-year-old man presented with low back pain and paresthesia.MRI of the thoracolumbar spine revealed an intramedullary mass lesion at the T11 vertebral body level.The mass lesion was hypointense on T2WI and hyperintense on T1WI.Tumor resection was performed and the histologic result was melanotic schwannoma.CONCLUSION MMNST should be considered in the differential diagnosis when calcification or melanin is seen in an intradural spinal tumor.
