Three Years of Idiopathic Chylous Ascites: Splenic Marginal Zone Lymphoma Behind the Mask

TL;DR

An elderly man with long-standing chylous ascites was found to have splenic marginal zone lymphoma, highlighting the need for thorough diagnostic testing in such cases.

Contribution

This case report highlights the rare association of splenic marginal zone lymphoma with idiopathic chylous ascites.

Findings

A three-year case of refractory chylous ascites was linked to splenic marginal zone lymphoma.

PET imaging and bone marrow biopsy were critical in diagnosing the underlying lymphoma.

Ascitic fluid analysis showed T lymphocyte predominance without a detectable B-cell clone.

Abstract

Chylous ascites is rare in adults and is most commonly caused by lymphatic obstruction due to non-Hodgkin B-cell lymphoma. Splenic marginal zone lymphoma (SMZL) is an uncommon etiology. We report the case of an 89-year-old man with a three-year history of refractory chylous ascites initially considered of unknown origin. Clinical examination revealed significant ascites and splenomegaly. PET imaging demonstrated hypermetabolic lymphadenopathy, and bone marrow biopsy revealed infiltration by a CD5-/CD10- B-cell lymphoma consistent with SMZL. Analysis of ascitic fluid showed a predominance of T lymphocytes without a detectable B-cell clone. This case illustrates that SMZL, although rare, should be included in the differential diagnosis of persistent chylous ascites. A comprehensive diagnostic approach combining imaging, bone marrow biopsy, and flow cytometry is essential to establish a timely diagnosis and guide appropriate management, especially in elderly patients.

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