[Subacute pulmonary coccidioidomycosis: A differential diagnosis of lung cancer]

Coccidioidomycosis is a fungal infection endemic to the southwestern United States, particularly Arizona. Rare in Europe, it can lead to diagnostic delays insofar as its clinical and radiological features may mimic lung cancer, mycobacterial and/or bacterial diseases.

We report a case of pulmonary and mediastinal coccidioidomycosis diagnosed in France following travel to an endemic area by a 68-year-old immunocompetent woman, a former smoker, who presented with a persistent cough and constitutional symptoms (fatigue, weight loss and anorexia). Chest computed tomography revealed a paramediastinal mass in the middle lobe as well as ipsilateral mediastinal lymphadenopathy. Given the patient's age, clinical deterioration, and heavy smoking history, lung cancer was initially suspected but rapidly ruled out after direct examination, reverse transcription quantitative real-time polymerase reaction (RT-qPCR), and serology had confirmed the presence of coccidioidomycosis. Due to several risk severity factors, treatment with fluconazole was promptly initiated, leading to clinical and radiological improvement.

Rarely reported in France, pulmonary and mediastinal coccidioidomycosis can mimic the clinico-radiological presentation of bronchopulmonary cancer. Diagnosis relies on thorough travel history, careful assessment of symptoms, and mycological confirmation - often requiring repeated serological sampling.