[Pulmonary blastomycosis]

Blastomycosis is a rare fungal disease in Africa which is often due to inhalation of "Blastomyces dermatitidis". Pulmonary blastomycosis is the most common clinical manifestation which presents with a variety of clinical features, ranging from asymptomatic to rapidly fatal. We report the case of a Tunisian patient aged 35 years with no previous medical history, hospitalized with chronic cough, bilateral basithoracic pain, fever and weight loss. Clincal examination showed fever and left paravertebral subcutaneous swelling next to the tenth thoracic vertebra (T10). Chest imaging objectified bilateral alveolar and nodular opacities with excavations in some places. Sputum stain for Koch bacillus (BK) was negative (direct examination and culture). Bronchial fibroscopy was normal. Anatomopathological examination of dorsal mass biopsy revealed blastomycosis. The diagnosis was confirmed by cultures of the biopsic fragments of the mass. Antifungal therapy with itraconazole was started with clinical and radiological improvement. This case study highlights challenges in the diagnosis of blastomycosis in our country, in particular when lesions mimick tuberculosis; hence delayed therapy.