A case of pulmonary actinomycosis required to discriminate from pulmonary cancer invading the chest wall

Abstract

A 48-year-old woman presented swelling of anterior chest wall 10cm in diameter with redness and pain. A hematological examination revealed increased inflammatory response. Chest plain X-ray showed a tumorous mass in the right hilum of the lung. A chest CT scan revealed an irregularly shaped tumor 10cm in diameter with invasion into the chest wall and destruction of the costal cartilage. The tumor was localized between S³ and S⁵, and it was adjacent to the cardiac shadow. Aspiration biopsy was performed to make the final-diagnosis of invasive tumor. A purulent discharge flowed from the punctured site, and open drainage was made. A pathological study revealed sulfur granules composed of filamentous Druse with severe inflammation. The purulent discharge was incubated and Actinomyces israelii was isolated. From these findings, pulmonary actynomycosis was diagnosed, and ABPC administration was started. One month later, the tumor size decreased. The dosage of AMPC was continued for a further 6 months on an outpatient basis, and now the patient was closely followed up.
Actynomycosis should be considered as a differential diagnosis of tumor disease with invasive lesion.