Primary Bronchopulmonary Actinomycosis Masquerading as Lung Cancer: Apropos of Two Cases and Literature Review.

Actinomycosis is a rare and slowly progressive infectious disease that can affect a variety of organ systems including the lung. It is caused by filamentous Gram-positive anaerobic bacteria of the genus Actinomyces. Despite its rarity, pulmonary actinomycosis can involve lung parenchyma, bronchial structures, and chest wall. The disease can mimic lung malignancy given its nonspecific clinical and radiological presentation, thus posing a diagnostic dilemma to the attending physician. In this paper, we describe two patients with pulmonary actinomycosis mimicking bronchogenic carcinoma; the former presented with peripheral infiltrate and associated hilar/mediastinal lymphadenopathy and the latter presented with a foreign body-induced endobronchial mass. Clinical, imaging, diagnostic, and therapeutical aspects of the disease are discussed, demonstrating the paramount importance of the histological examination of lung tissue specimens in the confirmation of the infection given either its low culture yield or the limited use of new molecular diagnostic tools in routine clinical practice.