Coincidental occurrence of actinomycosis and Ewing's sarcoma in a child.

Pulmonary consolidation, rarefaction of adjacent ribs and pleural effusion, a triad frequently considered characteristic of actinomycosis, seemed in the present case to support this serologically entertained diagnosis. However, the subsequent course of disease disclosed the most uncommon association of actinomycosis an metastatic Ewing's sarcoma of the lung. The possibility of combined occurrence of an opportunistic infection by actinomyces and malignancy, calls for open biopsy in cases not responding to penicillin treatment or with an unexpected evolution of the clinical manifestations.