Unusual Clinical Presentation of BCell Prolymphocytic Leukemia Cases as Splenic Marginal Zone Lymphoma Effectively Treated With Rituximab Monotherapy summary

In this episode, Britany and Seth discuss Sachanas et al.'s retrospective case series of five patients with massive splenomegaly and prolymphocytosis who clinically resembled splenic marginal zone lymphoma (SMZL) but fulfilled criteria for B-cell prolymphocytic leukemia (B-PLL). Despite >55% circulating prolymphocytes, bone marrow infiltration and immunophenotyping were SMZL-like. No MYC rearrangements or TP53 deletions were found; one patient exhibited a 7q31 deletion, supporting SMZL-variant classification. Rituximab monotherapy yielded a complete remission rate of 40% and prolonged responses in 80%, suggesting potential for less toxic, effective therapy in elderly or frail patients. The discussion covers diagnostic challenges, the risk of misclassification, and treatment implications, emphasizing comprehensive workups (morphology, immunophenotyping, cytogenetics) and multidisciplinary care. Limitations include small sample size and retrospective design; future directions include molecular profiling, routine cytogenetic screening, prospective trials, maintenance Rituximab, and exploration of targeted therapy combinations.