Splenic Marginal Zone Lymphoma Presenting with Progressive Splenic Infarction and Acute Cholestatic Liver Injury- a Case Report

Abstract Background Splenic marginal zone lymphoma (SMZL) is a rare, indolent non-Hodgkin lymphoma. Progressive splenic infarction and acute cholestatic liver injury are uncommon complications, and their concurrent presentation has not been previously reported. Case Description A 76-year-old woman with remote breast cancer history and chronic splenomegaly with pancytopenia presented with worsening left-sided abdominal pain. Labs revealed pancytopenia and cholestatic liver injury. CT demonstrated a 22-cm spleen with multiple wedge-shaped infarcts and mildly heterogeneous hepatic enhancement. PET/CT showed diffuse splenic hypermetabolism, hypermetabolic periportal lymph nodes, and mildly increased bone marrow FDG uptake. Hemolysis workup including direct antiglobulin test and cold agglutinin titer was negative. Hepatitis B and C serologies were negative. D-dimer was markedly elevated at 3,840 ng/mL. MRCP excluded biliary obstruction. Percutaneous splenic core biopsy revealed nodular and intrasinusoidal infiltration by atypical B lymphocytes. Immunohistochemistry showed CD20, PAX5, and IgM positivity with kappa restriction; CD5, CD10, CD23, CD103, and cyclin D1 were negative. CD21 highlighted follicular dendritic cell meshworks colonized by neoplastic cells. The patient was staged as Ann Arbor stage IV. Rituximab monotherapy was initiated with clinical improvement. At 6-month follow-up, liver function normalized, cytopenias resolved, splenic size decreased from 22 to 17 cm, and PET/CT demonstrated partial metabolic response. Significance This is the first reported case of SMZL with concurrent splenic infarction and cholestatic liver injury. It highlights the diagnostic utility of splenic core biopsy with an expanded immunohistochemical panel and the efficacy of rituximab monotherapy in this clinical context.