[Case 6: Pulmonary histoplasmosis presenting as a pseudo-tumoral lesion].

Infectious pulmonary pseudo-tumoral lesions represent a significant diagnostic pitfall, as they can mimic primary lung carcinoma and may result in delayed diagnosis and treatment. They include a broad spectrum of etiologies, ranging from common infections such as tuberculosis, aspergillosis, actinomycosis, and histoplasmosis to rarer bacterial and fungal causes. Among these etiologies, pulmonary histoplasmosis may present as a nodular pseudo-tumoral lesion. Although rare in Europe, this diagnosis should be considered even in immunocompetent patients, particularly if they traveled to endemic zones. Histopathologically, histoplasmosis is characterized by granulomatous lesions, often with necrosis, associated with the presence of small yeasts that can be highlighted using special stains. The morphological differential diagnosis includes other yeast-like fungal infections, particularly cryptococcosis and pneumocystosis. In this context, etiological identification relies on careful morphological analysis, complemented by microbiological investigations and molecular techniques. An integrated approach, taking into account clinical data and patient history, is essential to avoid diagnostic errors and guide appropriate treatment decision-making.