Abstract Details

Title Brainstem Small Lymphocytic Lymphoma (SLL) Presenting as Serpiginous Small Vessel Enhancement and Peduncular Hallucinosis: A First Case Report

Topic Neuro-oncology

Presentation(s) P15 - Poster Session 15 (5:30 PM-6:30 PM)

Poster/Presentation
Number 4-005

Background Small Lymphocytic Lymphoma (SLL), presenting as primary central nervous system (CNS) lymphoma, is a rare entity. Radiographic appearance is not well described. Indolent clinical history of low-grade lymphoma often dissuades clinicians from considering lymphoma. Brainstem lesion diagnosis is challenging due the high biopsy morbidity and mortality. We present a case of peculiar serpiginous small vessel enhancement suggestive of inflammatory vasculitides or lymphoproliferative disease. To our knowledge, this is a first report of primary CNS SLL infiltrating the brainstem.

Objective We present a case of a 72-year-old male with a 2-year-history of peduncular hallucinosis, progressive ataxia, bilateral facial pain and dysgeusia found to have SLL infiltrating the midbrain, cerebral peduncle and pons.

Design/Methods N/A

Results Neuroimaging revealed a dorsal pontine-midbrain abnormality with serpiginous small vessel enhancement coalescing into periventricular uniformly enhancing masses. A large volume cerebrospinal fluid (CSF) sample was hand-delivered to minimize degradation. Flow cytometry revealed an immunophenotypically abnormal CD5+ B-cell population, despite normal nucleated cell count (3 cells/microliter). Bone marrow biopsy confirmed low-grade CD5+/CD23+ B-cell lymphoma, consistent with CNS SLL. Review of literature revealed additional cases of CNS SLL with similar CSF involvement and periventricular infiltration. Patient was treated with rituximab and high-dose methotrexate. Peduncular hallucinosis resolved after 2 cycle, and a full radiographic response was achieved after 7 cycles.

Conclusions This is a rare case of brainstem SLL diagnosed with CSF flow cytometry, bone marrow biopsy and treatment response. Given the rarity of this entity, there are no pathognomonic radiographic findings. Along with previous cases reports, we suggest that CNS low grade lymphoma can present with paradoxical indolent clinical course developing over years, juxtaposed with diffuse serpiginous small vessel enhancement coalescing into periventricular uniformly enhancing masses. Recognition of CNS SLL as a differential, avoiding corticosteroids prior to diagnosis, was paramount to good treatment outcome.

Authors/Disclosures
Brigitte Reina, MD (UT Health) PRESENTER	Dr. Reina has nothing to disclose.
Amy Chan, MD (Dartmouth-Hitchcock Medical Center)	Dr. Chan has nothing to disclose.