SHM Converge Scientific Abstract ePoster Gallery-The Cavitary Curveball: Blastomycosis Mimicking Tuberculosis in a Healthy Young Man

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This case report describes a 35-year-old previously healthy man who developed a prolonged febrile illness with nausea, vomiting, dry cough, malaise, night sweats, anorexia, and an 11% unintentional weight loss over three months. Because of cavitary pulmonary nodules and mediastinal/hilar lymphadenopathy on CT, the initial differential diagnosis included tuberculosis, malignancy, and autoimmune disease such as vasculitis or sarcoidosis.<br /><br />The patient had recent travel to Alaska and a Caribbean cruise, and he worked as a carpenter remodeling older homes, suggesting possible environmental exposure. Extensive infectious workup was largely negative, including testing for tuberculosis, histoplasmosis, coccidioidomycosis, fungal markers, and cultures from sputum, bronchoalveolar lavage, lung biopsy, and lymph node samples. Despite these negative results, Blastomyces antibody testing by EIA was positive, supporting the diagnosis of pulmonary blastomycosis.<br /><br />Blastomycosis is a systemic fungal infection caused by Blastomyces dermatitidis or Blastomyces gilchristii, acquired by inhalation of airborne conidia. It can present with mild respiratory symptoms or severe pneumonia and may disseminate to other organs. Although uncommon, it can closely mimic tuberculosis or lung cancer, especially when cavitary lesions and lymphadenopathy are present.<br /><br />The patient was treated with itraconazole 200 mg every eight hours and improved clinically. A repeat CT scan three months later showed radiographic improvement. Antifungal therapy was later stopped after repeat Blastomyces antigen testing and fungal cultures were negative.<br /><br />This case highlights the importance of keeping blastomycosis in the differential diagnosis of cavitary lung disease, particularly in immunocompetent patients with compatible travel or environmental exposures. Early fungal testing and timely treatment can prevent delays and reduce morbidity.

Asset Subtitle

Rashma Sadasivan

Meta Tag

Author List Conrad Czejdo, Harry Boamah, Rashma Sadasivan

Category Clinical Vignettes

Concept Pulmonary Blastomycosis

Concept Diagnostic Workup

Concept Itraconazole

Concept Constitutional Symptoms

Concept Pulmonary Findings

Distinguished Non-Finalist

Presenter Organization Western Michigan University Homer Stryker M D School of Medicine, Kalamazoo, Michigan

Presenting Author Rashma Sadasivan

Track Adult

Keywords

blastomycosis

cavitary pulmonary nodules

mediastinal lymphadenopathy

febrile illness

pulmonary fungal infection

Blastomyces dermatitidis

itraconazole treatment

immunocompetent patient

differential diagnosis

environmental exposure

Pulmonary Blastomycosis

Diagnostic Workup

Itraconazole

Constitutional Symptoms

Pulmonary Findings