Presentations of chronic cavitary pulmonary histoplasmosis mimic infected cystic bronchiectasis in an immunocompetent host: A case report

Abstract

Background: Chronic cavitary pulmonary disease and laryngeal involvement are unusual manifestations of Histoplasmosis capsulatum infection, particularly in patients who are not immunocompromised. The presence of fibro-cavitary lesions has been reported as a radiologic presentation of chronic histoplasmosis in patients with pre-existing lung disease. However, there have been few reports of extensive basal predominant cavitary lesions that mimic cystic-bronchiectasis.

Case presentation: A 65-year-old previously healthy Thai male presented with productive cough, hoarseness, low-grade fever, and weight loss for 6 months. There was no history of significant exposure to Histoplasmosis capsulatum. Tests for HIV and anti-IFN- $\gamma$ antibody were negative. Chest CT revealed multifocal thick wall cavities, which were distributed in a peri-bronchial pattern, and some areas of consolidation in both basal lungs. Laryngoscopy revealed an ulcerative lesion of the false vocal cords. Histopathological study of false vocal cords and lung tissue showed granulomatous inflammation with mixed inflammatory cell infiltration and aggregation of histiocytes containing round intracytoplasmic organisms. GMS-staining was positive, but negative mucicarmine-staining was negative. A real-time PCR assay of the lung tissue was positive for Histoplasmosis capsulatum. The final diagnosis was chronic cavitary pulmonary histoplasmosis with laryngeal involvement.

Conclusion: Chronic cavitary pulmonary histoplasmosis is rare, as is laryngeal involvement. However, there have been such cases in endemic areas, even in immunocompetent patients. Chronic histoplasmosis should be considered in patients who present with the extensive basal predominant cavitary-pulmonary lesions that mimic cystic bronchiectasis.

Keywords: Case report; Cavitary lung disease; Fungal infection; Histoplasmosis; Laryngeal histoplasmosis.

Fig. 1

A. Direct laryngoscopy revealed a yellowish inflamed lesion at the right false vocal cord B. Chest radiography revealed multifocal thick wall cavitary lesions and air-fluid level C. Chest CT at the upper trachea showed multiple irregular thick wall cavities D. Chest CT at the lower lung zone revealed multifocal cavitary lesions that connect to the bronchus and mimic cystic-bronchiectasis, multifocal consolidation, and ground-glass opacity and large pleural based cavities with air-fluid level at the posterior segment of the left lower lung.

Fig. 2

Biopsy of the larynx and lungs A. Histopathologic findings of tissue from the larynx revealed multinucleated giant cells (yellow circles), which contained intracellular organisms B. GMS staining of tissue from the larynx showed organisms 2–4 μm in diameter with internal septation C. PAS staining of tissue from the larynx showed numerous intracellular organisms D. H&E staining of lung tissue revealed histocytes with numerous intracellular organisms E. GMS staining of the lung tissue was positive for yeasts. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)