First Incidence of Parietal Lobe Metastasis in an Adult with Desmoplastic/Nodular Medulloblastoma: A Case Report and Review of the Literature

Abstract

Abstract Background: Medulloblastoma in adults is a rare and highly aggressive central nervous system (CNS) tumor, representing less than 1% of all brain tumors. Supratentorial metastasis is uncommon, and extraneural metastasis occurs in approximately 5% of cases, primarily in frontal and temporal lobes. Here, we present a unique case of parietal lobe metastasis in an adult with desmoplastic/nodular medulloblastoma, adding a novel dimension to the existing knowledge base. We conducted a thorough search on the PubMed database to explore prior cases and establish the uniqueness of our case. Case presentation: A 46-year-old male with a posterior fossa tumor and hydrocephalus was diagnosed with medulloblastoma seven years ago. Adjuvant concurrent chemoradiotherapy was administered after surgery. After five years, a surveillance brain MRI suggested possible tumor recurrence. A whole-body bone scan revealed widespread bone marrow metastases. Despite receiving adjuvant therapy in the past two years, the patient has experienced progressive right hemiparesis, ataxia, and gait disturbances. A brain MRI showed a distinct 6 x 4 x 2 cm in the left parietal lobe. The patient's tumor was entirely removed, initially suspected to be a parasagittal meningioma. However, it was identified as a supratentorial metastasis of desmoplastic/nodular medulloblastoma after a thorough histopathological examination. Conclusion: Considering the possibility of tumor recurrence or intracranial metastasis in medulloblastoma patients is crucial. Regular treatments and follow-ups are strongly recommended to detect any signs of reoccurrence in these atypical presentations promptly.