Differentiating Thoracic Actinomycosis from Lung Cancer

Thoracic actinomycosis can masquerade as primary or metastatic lung cancer. In some cases, the infection and cancer coexist. In this report, we present the clinical, radiologic, and pathologic findings of 8 patients with thoracic actinomycosis who were referred to the University of Texas MD Anderson Cancer Center with presumed lung cancer. The most common symptoms were chest pain and cough. Radiographic imaging showed poorly defined masses equally distributed in both lungs. In most cases, the diagnosis of actinomycosis was not determined by clinical differential assessment but by bronchoalveolar lavage and thoracotomy with excisional lung biopsy.