LAUSR

tps://doi.org/10.1016/j.jds.2021.04. 91-7902/a 2021 Association for Denta e CC BY-NC-ND license (http://creati Actinomycosis is a chronic and slowly progressive granulomatous disease caused by the filamentous Gram-positive anaerobic bacteria. The actinomycotic bacteria mainly infect cervicofacial, thoracic, and abdominal regions of the human body, but they can also cause periapical infection through the infected root canal of a tooth, which is also called as periapical actinomycosis. Here, we reported a case of periapical granuloma (PG) with actinomycosis at the periapical area of tooth 25 in a 32-year-old male patient. This 32-year-old male patient came to our dental clinic for evaluation and treatment of mild pain and a sinus tract at the periapical area of tooth 25 for one month. Periapical radiography revealed a well-defined radiolucent lesion measuring 8 mm in greatest diameter at the periapical area of tooth 25. The clinical diagnosis was either a radicular cyst or a PG. After discussing with the patient, the treatment plan for this diseased tooth was endodontic treatment followed by periapical surgery. Thus root canal therapy was done first and the periapical surgery was performed under local anesthesia one week after the root canal therapy. During the surgery, fenestration of the buccal cortical plate at the periapical area of tooth 25 was found. Two small pieces of brownish soft tissues were enucleated and sent for histopathological examination. Microscopically, one relatively large piece of soft tissue specimen showed a vascularized fibrous connective tissue with foci of hemorrhage and a severe lymphoplasma cell infiltrate (Fig. 1AeC). The other small piece of soft tissue was an actinomycotic colony with pale blue and red