Chronic sinusitis unresponsive to medical therapy: a case of maxillary sinus actinomycosis focusing on computed tomography findings.

Actinomycosis of the paranasal sinuses is a rare occurrence and its clinical presentation does not suggest a specific diagnosis. Therefore, actinomycosis should be included in the differential diagnosis of neoplasms and granulomatous lesions of the head and neck region. However, the differentiation from a malignant neoplasm is not easy because the radiological findings are frequently similar and positive cultures are difficult to obtain. This report highlights the clinical progress of paranasal actinomycosis associated with some computed tomography findings that can be extremely helpful in the correct diagnosis. The characteristics of the disease are described and the relevant literature is discussed.