A Case Report on Carcinomatous Meningitis in a Patient With Double-Hit Lymphoma.

A double-hit lymphoma is a high-grade B-cell lymphoma (HGBCL) with MYC and BCL2/BCL6 rearrangements. It is characterized by a rapidly progressive advanced disease, high rates of central nervous involvement (CNS), refractoriness to conventional chemotherapy, and poorer clinical outcomes. Carcinomatous meningitis is a condition in which cancer cells metastasize to the meninges without involving the brain parenchyma; this phenomenon has also been reported in the literature by other terms like "leptomeningeal meningitis," "leptomeningeal carcinomatosis," "leptomeningeal metastasis," or "neoplastic meningitis." This form of CNS involvement has been described as an infrequent complication with the trajectory of this aggressive lymphoma. We report an illuminating case of a 63-year-old male diagnosed with double-hit lymphoma, which was complicated by fatal carcinomatous meningitis.