Tumor mimicking actinomycosis of the upper lip: report of two cases

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Peculiar findings of orofacial actinomycosis mimicking the clinical appearance of a tumor of the upper lip were reported. A 68-year-old woman (case 1) and a 62-year-old woman (case 2) visited our hospitals towards the end of 2004 and 2007; the clinical diagnosis for each patient was upper labial tumor, and the lesions were surgically removed. Histologically, the excised specimens showed granulomas including bacterial colonies consisting of club-shaped filaments that formed a radiating rosette pattern in the submucosal layer. DNA samples were extracted from paraffin sections and examined by PCR for Actinomyces species. The PCR products examined by direct DNA sequencing demonstrated the presence of Actinomyces israelii and Actinomyces gerencseriae in both case 1 and case 2. Finally, pathological diagnoses of actinomycosis were made for each. Actinomycosis mimicking a tumor is very uncommon in the oral mucosa, and the use of PCR is an effective means of early and accurate diagnosis.