Unusual case of bifocal leptomeningeal melanocytoma in the posterior fossa with seeding in the spinal canal

Abstract

A 26-year-old man presented with signs of raised intracranial pressure. CT and MRI of the head demonstrated two separate lesions in the posterior fossa. The radiological differential diagnoses included multiple meningiomas, schwannomas, neurofibromas and subependymomas. Both lesions were surgically resected. Histopathological examination revealed localisations of a leptomeningeal melanocytoma. Leptomeningeal melanocytoma is a rare tumour of the central nervous system. Generally, it has a good prognosis if radical resection can be performed. In cases of subtotal resection, adjuvant radiotherapy should be considered. Local recurrences are common. Less frequently, leptomeningeal metastases and, on rare occasions, distant metastases or progression to malignant melanoma have been described. We describe an unusual case with multiple localisations of melanocytoma in the posterior fossa and spinal canal, with the emphasis being on the radiological findings and diagnosis of this rare tumour. After surgery of the brain, this patient was irradiated on the craniospinal axis.