Detection of pulmonary actinomycosis by metagenomic next-generation sequencing in a cancer patient receiving maintenance olaparib: A review and case report

A 52-year-old female patient receiving olaparib maintenance treatment was admitted to hospital with a low fever and chest tightness. A CT scan of the patient's chest showed diffuse ground glass shadow or miliary nodular shadow in the bilateral lungs. Her inflammatory biomarkers were almost normal, except the slightly elevated C-reactive protein. Moreover, lymphocytes count obviously decreased. Empirical treatment did not relieve her symptoms, while traditional testing developed negative results. The results of metagenomic next-generation sequencing (mNGS) revealed the presence of a potential pathogen, Actinomyces odontolyticus (A. odontolyticus), in bronchoalveolar lavage fluid (BLAF). Once large-dosed penicillin G was administered, the fever returned to normal and chest tightness disappeared. Reexamination of chest CT revealed that the pulmonary lesions was almost absorbed. Our case demonstrated that mNGS is a novel approach to identify pathogens sensitively and accurately, especially for uncommon and atypical infection.