Abstract Details

Title Discrepancy in CSF Flow Cytometry Results from Lumbar Puncture and Ventricular Sampling Leading to Delay in Diagnosis Recurrent CNS Lymphoma: A Case Report

Topic Neuro-oncology

Presentation(s) P4 - Poster Session 4 (11:45 AM-12:45 PM)

Poster/Presentation
Number 5-025

Objective N/A

Background Accurate diagnosis of Central nervous system (CNS) lymphoma, a rare and aggressive subtype of non-Hodgkin lymphoma, is essential for effective treatment planning and can be achieved by tissue biopsy or cytopathologic analysis of cerebrospinal fluid (CSF). We report a case of a 30-year-old man with recurrent CNS lymphoma in which CSF flow cytometry via lumbar puncture yielded persistently negative results while the presence of B-cell lymphoma was found when CSF was sampled from the lateral ventricle.

Design/Methods A case report

Results Case Presentation: The patient was initially diagnosed with Diffuse Large B-cell Lymphoma with non-germinal center phenotype, CD20+/CD5+/BCL2(weak)/BCL6+, and an atypical T-cell population, concerning for concurrent T-cell lymphoma with cytotoxic phenotype, involving the small intestine causing perforation. He underwent treatment with R-CHOP/R-EPOCH with complete systemic response. Ten months later the patient presented with cognitive decline. MRI of the brain and spine showed diffuse subependymal and leptomeningeal enhancement in the lateral, third, and fourth ventricles, brainstem, and upper cervical cord with focal C3-7 myelitis. Systemic imaging was negative for lymphoma. A total of 13 lumbar punctures over three months yielded CSF with atypical T-cells though no detectable malignant lymphoid cells by flow cytometry or cytology. Biopsy of an involved area of the meninges showed fibrosis without evidence of neoplastic, granulomatous, or infectious processes. CSF flow cytometry from the ventricle promptly demonstrated the presence of B-cell lymphoma cells. This diagnostic challenge prompted further treatment.

Conclusions The incongruent CSF flow cytometry results from lumbar puncture and ventricular sampling underscores the importance of considering alternative sampling sites, such as cisternal or ventricular, when faced with persistently negative CSF results from a lumbar puncture, where there remains clinical concern for CNS lymphoma.

Authors/Disclosures
Neil Sielski, MD (NYU Langone Brain & Spine Tumor Center) PRESENTER	Dr. Sielski has nothing to disclose.
Christian Grommes, MD (Memorial Sloan-Kettering Cancer Center)	Dr. Grommes has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Ono. Dr. Grommes has received personal compensation in the range of $500-$4,999 for serving as a Consultant for BTG. Dr. Grommes has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Roche. Dr. Grommes has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Curis. Dr. Grommes has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Ono.
Lauren Schaff, MD, FAAN (Memorial Sloan Kettering Cancer Center)	Dr. Schaff has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Guidepoint. Dr. Schaff has received personal compensation in the range of $500-$4,999 for serving as a Consultant for BTG, plc. The institution of Dr. Schaff has received research support from BTG, plc. Dr. Schaff has received personal compensation in the range of $500-$4,999 for serving as a Speaker with Ono.
Elena Pentsova, MD (Memorial Sloan-Kettering Cancer Center)	The institution of Dr. Pentsova has received research support from YmAbs Therapeutics, Inc.

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