Central Nervous System Lymphoma in a Patient with Chronic Lymphocytic Leukemia: A Case Report and Literature Review

Abstract

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia that affects older adults in the Western world. Symptomatic nervous system invasion in undiagnosed CLL is rare, poorly understood, challenging to treat, and associated with decreased survival. The average survival of CLL patients with central nervous system (CNS) involvement is 3.79 years as compared to six years in CLL patients without CNS involvement. Autopsy studies demonstrated a high incidence of undiagnosed CLL with CNS involvement, suggesting that CNS involvement is either underdiagnosed or subclinical. Although the most common site of CNS involvement is the leptomeninges, our case demonstrates an extremely rare form of CNS diffuse large B-cell parenchymal involvement in a patient with a concurrent diagnosis of systemic CLL.

Keywords: central nervous system; chronic lymphocytic leukemia; neurologic involvement; primary central nervous system lymphoma.

Figure 1. Preoperative brain MRI and histopathological studies of the resection specimen

(1A, 1B) Preoperative axial and sagittal sections, post-contrast T1 magnetic resonance imaging (MRI) of the brain, showing a midline, supra-vermilion homogeneously enhancing lesion causing a significant mass effect and obstruction on the aqueduct. (1C, 1D) Preoperative sagittal sections, T1 and T2 MRI of the brain showing an isointense lesion on both sequences (arrow). (1E, 1F) Preoperative axial sections, T2 magnetic resonance imaging (MRI) of the brain showing dilated third and lateral ventricles. (1G) Postoperative sagittal T1 magnetic resonance imaging (MRI) of the brain. (1H) Low power view of the resection specimen revealing an infiltrating, angiocentric neoplasm associated with abundant necrosis (Hematoxylin and Eosin, 100X). (1I) High power view demonstrating mitotically active, malignant lymphoid cells, with open chromatin, nuclear membrane irregularities, and prominent-often multiple-nucleoli (Hematoxylin and Eosin, 400X). (1J) Immunohistochemistry for CD20 was diffusely positive (100X). (1L) Low power view of the bone marrow core biopsy revealing involvement by well-circumscribed, non-paratrabecular lymphoid aggregates (Hematoxylin and Eosin, 100X). (1M) High power view demonstrating a monomorphic population of small to medium-sized lymphoid cells with mild cytologic atypia (Hematoxylin and Eosin, 400X)