A Rare Case of Isolated Pulmonary Involvement in Lymphoid Variant Hypereosinophilic Syndrome

In 2020, a case study was presented of a 70-year-old male with isolated pulmonary involvement in lymphoid variant hypereosinophilic syndrome (L-HES), a rare condition typically characterized by skin manifestations. The patient, who had a history of hypertension and coronary artery disease, presented with progressive exertional dyspnea, dry cough, weight loss, fatigue, and anorexia, without recent travel or animal interaction. Despite recurrent admissions for presumed sinusitis and pneumonia, extensive testing including bronchoalveolar lavage and bone marrow biopsy revealed marked eosinophilia without evidence of malignancy or common mutations associated with myeloproliferative neoplasms. A clonal T-cell gamma chain gene rearrangement was identified, leading to a diagnosis of L-HES with pulmonary involvement. The patient responded well to corticosteroid treatment, with gradual improvement in symptoms and eosinophil counts. This case underscores the importance of a thorough evaluation in patients with hypereosinophilia to exclude secondary causes and identify rare presentations like isolated pulmonary L-HES.