Posterior Uveitis in Ocular-Involving Chronic Lymphocytic Leukemia and the Utility of Negative MYD88 L265P Testing in the Diagnosis

Abstract

<b><i>Introduction:</i></b> The aim of this study was to investigate if a negative test result for <i>MYD88</i> L265P mutation, associated with vitreoretinal lymphoma (VRL) and primary CNS lymphoma, in liquid biopsies from intraocular fluids can be a useful adjuvant test to diagnose chronic lymphocytic leukemia in clinically challenging cases. <b><i>Case Presentations:</i></b> We selected patients with a past medical history or examinations findings suspicious for intraocular lymphoma. We evaluated both vitreous and aqueous humor-derived (AHD) <i>MYD88</i> L265P mutation from patients that had suspected intraocular lymphoma that warranted a liquid biopsy procedure. Gold-standard cytopathology, flow cytometry, and gene rearrangement studies were also performed. All 4 patients had negative AHD <i>MYD88</i> L265P mutation testing. Gold-standard testing (cytology) either showed paucicellular specimens (1/4) or specimens with high background inflammation (3/4). One case showed a rare B-cell clonal population (CD5⁺, Kappa-restricted by flow cytometry), but this was not sufficient to make any definitive diagnosis. All patients were subsequently initiated on systemic therapy and had improvement in their disease burden. <b><i>Conclusions:</i></b> Negative AHD <i>MYD88</i> L265P mutation testing can serve as an adjuvant molecular test to diagnose difficult cases of intraocular CLL.