Secondary diffuse choroid plexus B-cell lymphoma: a case report and review of the literature

Background Central nervous system (CNS) relapse is an uncommon complication of diffuse large B cell lymphoma and is associated with significant mortality and morbidity. It is becoming a more prevalent pathologic entity in the rituximab era. Our case provides insight into the pathophysiology, diagnosis, prevention, and management of secondary intraventricular CNS lymphomas. Case Description We report an unusual case of a 64-year-old man who presented with an isolated secondary CNS lymphoma involving the choroid plexus in a diffuse pattern. He initially presented with obstructive hydrocephalus from diffuse choroid plexus lesions and was commenced on systemic therapy after confirmation of diagnosis via samples obtained from an open biopsy. Conclusions This case highlights the lack of high-quality evidence behind the use of high-dose intravenous methotrexate as CNS prophylaxis. The case provides additional insight into the pathophysiology of intraventricular CNS lymphomas and the importance of establishing a histopathologic diagnosis via an open biopsy before the administration of high-dose steroids.