Objectives: Hypereosinophilic syndromes (HSS) are a rare group of heterogeneous disorders characterized by prominent and persistent eosinophilia and organ dysfunction. Secondary causes of eosinophilia must be excluded. Recent advances in molecular biology and cytogenetics have permitted the characterization of different subsets of hypereosinophilic syndrome. We describe a patient with the lymphocytic variant.
Patient: A 46-year old male Philippine patient presented skin lesions, fever, red eyes, enlarged lymph nodes and marked eosinophilia.
Results: Lymphocytic phenotyping by flow cytometry analysis was performed on peripheral blood and an aberrant population of T lymphocytes CD3-CD4+ producing interleukin 5 was found. TCR gene rearrangement using PCR amplification confirmed T cell clonality.
Conclusions: The lymphocytic variant of the hypereosinophilic syndrome is a primitive lymphocytic disorder characterized by a non-malignant T cell population expansion producing eosinophilopoietic cytokines, with an indolent clinical course but that can transform into a peripheral T lymphoma. We report the first case of such a variant published in our country and review the characteristics of this variety.