Rare incidence of parietal lobe metastasis in an adult with desmoplastic/nodular medulloblastoma: A case report and review of the literature.

ABSTRACT

INTRODUCTION AND IMPORTANCE 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 extra-neural metastasis occurs in approximately 5 % of cases, primarily in frontal and temporal lobes. Here, we present an exceptional case of parietal lobe metastasis in an adult with desmoplastic/nodular medulloblastoma. To explore prior cases and establish the uniqueness of our case, we conducted a thorough search on the PubMed database. CASE PRESENTATION A 46-year-old male, who was previously treated for medulloblastoma with surgery and adjuvant chemoradiotherapy seven years ago, presented with clinical symptoms suggestive of potential tumor recurrence. Despite two years of dedicated adjuvant chemoradiotherapy, the patient exhibited progressive right hemiparesis, ataxia, and gait disturbances. Subsequent brain magnetic resonance imaging (MRI) revealed a distinct 6 × 4 × 2 cm lesion in the left parietal lobe, which, upon post-operative histopathological examination, was identified as a supratentorial metastasis originating from desmoplastic/nodular medulloblastoma. CLINICAL DISCUSSION: Medulloblastomas, once categorized as primitive neuroectodermal tumors (PNET), are now distinctly classified as high-grade embryonal tumors, mainly characterized by their histological features and cellular origin. Common clinical presentations include hydrocephalus, headache, unsteady gait, and truncal ataxia. Surgical intervention aims for radical excision, complemented by vital adjuvant chemoradiotherapy to minimize recurrence risk. CONCLUSION: Considering the possibility of tumor recurrence or intracranial metastasis in patients with medulloblastoma is crucial. Therefore, regular follow-ups are strongly recommended to promptly detect any signs of reoccurrence in these atypical presentations.