Oto-laryngeal histoplasmosis

Metagenomic next-generation sequencing identified Histoplasma capsulatum in the lung and epiglottis of a Chinese patient: A case report

Histoplasmosis is an endemic disease mainly occurring in North America and is rare in China. Confirmation of histoplasmosis should be based on a compatible clinical scenario and a positive culture or histopathology. However, there are still many cases that are misdiagnosed or missed, especially in individuals from non-endemic areas. In recent years, metagenomic next-generation sequencing (mNGS) has led to the accurate and timely diagnosis of some rare and complicated infectious diseases. We describe the case of a 27-year-old Chinese man who had chronic progressive pulmonary lesions without any symptoms for more than 1year, until the lesions reached the epiglottis and led to progressive pharyngeal pain. There were no positive results from bronchoalveolar lavage fluid (BALF) and epiglottis tissue cultures, or from epiglottis and lung pathological examinations, but mNGS was able to identify Histoplasma capsulatum in the epiglottis tissues and BALF as the cause of the lesions. The patient was treated successfully with itraconazole.

Laryngeal Histoplasmosis

Histoplasma capsulatum is an endemic fungus found in moist, fertile soil; in North America, it is most prevalent in the river valleys of the central United States. Most primary infections in the immunocompetent host are asymptomatic or are thought to be a flu-like illness. Disseminated histoplasmosis most commonly occurs in immunosuppressed patients. Histoplasmosis infection involving the larynx is an extremely rare manifestation. Here, we describe the case of an immunocompetent man with symptomatic, acute pulmonary histoplasmosis with laryngeal involvement who presented with a chief complaint of hoarseness. We also review the literature of immunocompetent patients with laryngeal histoplasmosis.

Histoplasmosis of the larynx

INTRODUCTION

Laryngeal histoplasmosis was first described in 1952. Since then, fewer than 100 cases had been reported. This dimorphic fungus is endemic in the Mississippi and Ohio River Valleys. The yeast phase is responsible for human infection.

METHODS

We report a 44-year-old woman who developed laryngitis. The markedly abnormal larynx, which could have been mistaken for papillomatosis, was biopsied, at which time the diagnosis of histoplasmosis was confirmed. Treatment with oral ketoconazole was instituted.

RESULTS

Objective voice assessment showed abnormalities of maximum phonation time, speaking fundamental frequency, perturbation, percent voicing, mean flow rate, and spectral pattern. Subsequent to antifungal therapy, objective measures were improved.

CONCLUSION

This represents the first case of laryngeal histoplasmosis in which response to therapy is documented by objective vocal assessment.

Histoplasmosis presenting as hyperplastic gingival lesion

A case of histoplasmosis presenting as ulcerated, hyperplastic gingiva and with no other systematic signs and symptoms is reported. The clinical presentation and the rarity of this condition led one of us to the differential diagnosis of a malignant lesion. The correct diagnosis was made after histological examination and tissue culture which yielded Histoplasma capsulatum. The patient was successfully treated with ketoconazole.