MS-30 * MENINGEAL MELANOCYTOMA WITH MULTIFOCALITY, RAPID CNS SEEDING, AND SYSTEMIC METASTASES

Abstract

OBJECTIVE: Meningeal melanocytomas are rare entities that range from benign and well-differentiated lesions with a favorable prognosis to higher-grade lesions that may undergo malignant transformation with subsequent CNS dissemination. Transition from a meningeal melanocytoma to primary CNS melanoma is particularly rare with only a handful of cases reported. Systemic spread of a transformed meningeal melanocytoma, an exquisitely rare occurrence, is, to the best of our knowledge, reported in only three cases. Here we report the case of a woman who initially presented with multifocal meningeal melanocytomas with subsequent rapid transformation, diffuse CNS seeding, and systemic metastases. CLINICAL PRESENTATION AND MANAGEMENT: A 43 year-old woman presented with headaches, nausea, and vomiting for two months with negative GI work-up. She experienced a syncopal episode with CT and MRI brain scans showing 3 dural-based lesions involving the foramen magnum, fourth ventricle, and right CPA. The patient underwent STR of the lesions; the anterior lesion was inaccessible. Pathology reported a melanocytoma with malignant features. A negative dermatology and ophthalmology work-up were performed. The patient received post-operative radiotherapy (50.4 Gy) to the posterior fossa. Six months following surgery she presented with new neurological symptoms, and MRI of the neuroaxis showed new leptomeningeal enhancement within the cerebellum, thoracic spine, and supratentorially. With neuro-oncology input, she was started on Temodar and underwent palliative spinal RT. Unfortunately she continued to experience pain, and follow-up MRI showed new intrathecal C-spine nodules. Abdominal imaging revealed multiple lung and liver metastases, with biopsy of a 7-cm liver lesion revealing malignant melanoma. The patient unfortunately continued to deteriorate and succumbed to her disease approximately 9 months following diagnosis. CONCLUSION: Meningeal melanocytomas are rare tumors that are not only challenging to diagnose, but challenging to clinically predict and manage. This case illustrates these challenges and the multidisciplinary response needed to optimize outcomes.