Primary Central Nervous System Lymphoma Presenting as a Solitary Fourth Ventricular Mass: A Case Report.

The occurrence of primary fourth ventricular lymphoma is an exceptionally uncommon phenomenon. Here, we present a case of lymphoma in the fourth ventricle in a 30-year-old male who presented with progressive headache and vertigo over the last one month of his presentation. Preoperative MRI revealed a space-occupying lesion of the fourth ventricle. Pathological analysis following complete resection confirmed the lesion as primary central nervous system lymphoma. The patient underwent chemotherapy following the MTR (methotrexate, temozolomide, and rituximab) protocol with four months of uneventful follow-up, indicating no disease recurrence. Therefore, clinicians are advised to consider the potential presence of lymphoma as part of the differential diagnosis for space-occupying lesions, especially when there is a combination of clinical deterioration and rapid imaging progression.