Symptomatic leptomeningeal carcinomatosis: a rare presentation of chronic lymphocytic leukaemia relapse.

Central nervous system (CNS) involvement in patients with chronic lymphocytic leukaemia (CLL) is very rare and, when present, it is frequently asymptomatic. Rather, CNS involvement is more common in other haematological malignancies such as mantle cell lymphoma or diffuse large B cell lymphoma. The paucity of literature on CNS involvement in CLL underscores the importance of increasing awareness about its presentation, diagnosis and optimal management. We describe a case of symptomatic leptomeningeal leukaemic involvement as an atypical presentation of CLL relapse. A favourable clinical response was observed following systemic monotherapy with venetoclax.