Drastically progressive lung cavity lesion caused by Actinomyces odontolyticus in a patient undergoing chemoradiotherapy: A case report and literature review

Publication date: Available online 14 October 2019Source: Respiratory Medicine Case ReportsAuthor(s): Takeshi Matsumoto, Yusuke Kusakabe, Masamitsu Enomoto, Naoki Yamamoto, Kensaku Aihara, Shinpachi Yamaoka, Michiaki MishimaAbstractPulmonary actinomycosis reportedly forms 15% of all cases of actinomycosis, and pulmonary Actinomyces odontolyticus is particularly rare. A 60-year-old man with a hoarse voice was referred to our hospital. Lung squamous cell carcinoma was diagnosed at the clinical tumor-node-metastasis stage of cT2N2M0, and concurrent chemoradiotherapy was initiated. Further, a small cavity was also detected in the left upper lobe, but it was observed. During chemoradiotherapy, the small cavity lesion rapidly increased accompanying infiltration, and administration of short-term antibiotics did not improve the patient's condition. Bronchoscopy did not show any diagnostic results. Although a rapidly progressive malignant lesion could not be excluded and surgical management was considered, resection could not be performed because of the tight adhesion of the mass. Therefore, bronchoscopy was performed again, and the bronchial lavage culture showed a positive smear for the Actinomyces species. Further, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), the bacteria was identified as A. odontolyticus. After long-term administration of amoxicillin, the lung cavity with infiltration gradually improved. To the best of our kno...
Source: Respiratory Medicine Case Reports - Category: Respiratory Medicine Source Type: research