Strongyloides Infection Presenting as a Granulomatous Pulmonary Mass: An Unusual Manifestation of a Common Parasite

Document Type

Conference Proceeding

Publication Date

5-2026

Publication Title

American Journal of Respiratory and Critical Care Medcine

Abstract

Strongyloides stercoralis is an intestinal nematode capable of causing chronic infection that may persist for decades due to its autoinfective life cycle. Pulmonary manifestations are well recognized during larval migration or hyperinfection; however, presentation as an isolated lung mass is exceedingly rare. Granulomatous inflammation secondary to Strongyloides has been described only in isolated case reports, often mimicking malignancy. We present a case of Strongyloides infection manifesting as a solitary apical lung mass with granulomatous inflammation and eosinophilia in an immunocompetent patient .A 75- year-old male with hypertension, hyperlipidemia, and benign prostatic hyperplasia was referred to the pulmonary clinic for evaluation of a left apical lung mass detected on CT chest. He initially presented with hoarseness of voice, leading to ENT evaluation and laryngoscopy that revealed left vocal cord dysfunction. Further imaging prompted referral for tissue diagnosis. Ion navigational bronchoscopy with transbronchial biopsy demonstrated granulomatous inflammation without malignant cells. Bronchoalveolar lavage revealed 4% eosinophils, and peripheral blood testing showed persistent eosinophilia of 10.5% (absolute 520/µL) documented over three years. Bacterial, fungal, and acid-fast cultures were negative. Given the chronic eosinophilia, a parasitic evaluation was performed, and peripheral blood PCR for Strongyloides stercoralis was positive. The patient denied travel to endemic regions, immunosuppression, or gastrointestinal symptoms. He was treated with ivermectin, resulting in symptomatic and laboratory improvement. Pulmonary involvement in Strongyloides infection usually occurs during the larval migratory phase or hyperinfection, typically presenting as diffuse in filtrates or alveolar hemorrhage. A focal granulomatous lesion represents an exceptional presentation. Granuloma formation likely reflects a localized hypersensitivity response to degenerating larvae or ova within pulmonary tissue. The coexistence of chronic eosinophilia and granulomatous inflammation highlights the complex Th2-mediated immune response characteristic of chronic helminthic infection. A review of the literature reveals only a few similar cases of Strongyloides presenting as a solitary pulmonary mass, often mistaken for neoplastic disease. Identification by molecular testing underscores the diagnostic value of PCR in atypical parasitic presentations when conventional stains and cultures are negative. This case emphasizes the importance of considering Strongyloides stercoralis in the differential diagnosis of granulomatous pulmonary lesions with eosinophilia, even in non-endemic settings. Early recognition and anti-helminthic therapy are essential to prevent misdiagnosis and avert the potentially fatal consequences of hyperinfection syndrome.

Volume

212

Issue

S1

First Page

S3386

Last Page

S3386

Comments

American Thoracic Society International Conference, May 15-20, 2026, Orlando, FL

DOI

10.1093/ajrccm/aamag162.4503

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