Actinomycosis and Sialolithiasis in Submandibular Gland

Actinomycosis is a subacute or chronic suppurative infection caused by Actinomyces species, which are anaerobic Gram-positive bacteria that normally colonize the human mouth and digestive and urogenital tracts. Cervicofacial actinomycosis is the most frequent clinical form of actinomycosis, and is associated with odontogenic infection. Characterized by an abscess and mandibular involvement with or without fistula, but the cervicofacial form of actinomycosis is often misdiagnosed because the presentation is not specific and because it can mimic numerous infectious and non-infectious diseases, including malignant tumors. We report a rare case of actinomycosis infection with coexisting submandibular sialolithiasis. The patient presented with a 1×1 cm abscess-like lesion below the lower lip. Punch biopsy of the lesion revealed atypical squamous cell proliferation with infiltrative growth, suggestive of squamous cell carcinoma. The patient underwent wide excision of this lesion, where the lesion was found to be an abscess formation with multiple submandibular sialolithiases. The surgical specimen was found to contain Actinomyces without any evidence of a malignant process. We assumed that associated predisposing factors such as poor oral hygiene may have caused a dehydrated condition of the oral cavity, leading to coexistence of actinomycosis and sialolithiasis.