Rare central nervous system lymphomas.

Central nervous system (CNS) lymphomas are rare malignancies characterised by lymphoid infiltration into the brain, spinal cord, cranial nerves, meninges and/or eyes in the presence or absence of previous or concurrent systemic disease. Most CNS lymphomas are of the diffuse large B-cell lymphoma (DLBCL) subtype for which treatment strategies, particularly the use of high-dose methotrexate-based protocols and consolidation with autologous stem cell transplantation, are well established. Other histopathological subtypes of CNS lymphoma are comparatively less common with published data on these rare lymphomas dominated by smaller case series and retrospective reports.

Herpes Simplex Necrotic Lymphadenitis Masquerading as Richter's Transformation in Treatment-Naive Patients With Chronic Lymphocytic Leukemia.

Richter's transformation from chronic lymphocytic leukemia (CLL) to aggressive lymphoma is a relatively rare event with well-characterised clinical and radiological features, and can typically be distinguished from infectious complications of CLL. Opportunistic infections in CLL happen predominantly in the context of immunosuppressive therapy and/or relapsed/refractory disease. Herpes simplex viral (HSV) lymphadenitis is a rare phenomenon in treatment-naive CLL patients with only six cases reported in the English-language literature.