Central nervous system involvement in indolent lymphomas.

Area of Science:

• Hematology
• Neurology
• Oncology

Background:

• Central nervous system (CNS) involvement is a known complication of aggressive non-Hodgkin's lymphomas (NHL).
• CNS involvement is rarely reported in indolent lymphomas, typically occurring after histological transformation.
• Previous large series reported CNS involvement in approximately 3% of indolent NHL cases.

Purpose of the Study:

• To investigate the characteristics and clinical course of CNS involvement in patients with indolent B-cell lymphomas.
• To highlight the rarity and unexpected nature of this complication in indolent NHL.

Main Methods:

• Retrospective review of seven patients (six female, one male) with indolent B-cell lymphomas and CNS involvement.
• Analysis of disease characteristics, neurological symptoms, and treatment outcomes.
• Evaluation of systemic and CNS lymphoma presentation, including histological subtypes and transformation.

Main Results:

• Patients median age at diagnosis of systemic and CNS lymphoma was 60 and 63 years, respectively.
• Histologies included small lymphocytic lymphoma, follicular lymphoma (grades I and II), and unclear low-grade histology.
• Neurological symptoms varied, with parenchymal, leptomeningeal, or both types of involvement observed.
• All patients had systemic lymphoma, mostly with bone marrow involvement; four transformed to high-grade histology.
• Treatment involved systemic and intra-cerebrospinal fluid chemotherapy, with some receiving radiotherapy.
• Five patients achieved CNS response, with a median survival of 2 years (range 1-9 years); three died of CNS disease.

Conclusions:

• CNS involvement is a rare and unexpected complication of indolent NHL.
• It should be considered in the differential diagnosis for patients with new neurological signs.
• This condition is treatable, and some patients experience a prolonged clinical course.