PMC5565635_01
Radiological course. (A) Chest X-ray obtained 4 months before transfer to our hospital showed infiltration in the left upper-middle lung. (B) Two months later, although the infiltration on his X-ray had gotten better, it did not continue to improve. (C) Two months after this, the infiltration had re-expanded on transfer to our hospital.
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His chest X-ray revealed a shadow in the upper-middle left lung lobe (Fig. 1A). Afterward, he was asymptomatic for the next two months, and although the infiltration on his X-ray had gotten better, it did not continue to improve (Fig. 1B). At a follow-up examination a further two months later, the infiltration on his chest X-ray had deteriorated (Fig. 1C), and he was then transferred to our hospital.
Histological images of transbronchial lung biopsy specimen revealed inflammatory cells, noncaseating epithelioid granulomas, and multinucleated giant cells in interstitial lung space (hematoxylin and eosin stain, x200).
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Therefore, bronchoscopy with trans-bronchial lung biopsy was performed that showed inflammatory cells, noncaseating epithelioid granulomas, and multinucleated giant cells in the interstitial lung space (Fig. 2).
(A/B) Chest computed tomography on transfer to our hospital showed low attenuation within consolidation in the left lung, which was crossing a fissure. (C) After the patient received antibiotic therapy for two months, his abnormal lung shadow showed apparent improvement.
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Chest contrast-enhanced computed tomography (CT) revealed a left lung mass lesion crossing a fissure with a central area of low attenuation (Fig. 3A-B). Contrast-enhanced whole-body CT showed no other lesions, and transthoracic echocardiography showed no evidence of infective endocarditis. He was diagnosed as having lung abscess due to actinomycosis, and after the patient received amoxicillin for two months, his abnormal lung shadow improved (Fig. 3C).
Microscopic findings of aspirated frank pus showed Gram-positive coccobacilli (arrowheads) and Gram-negative cocci (closed arrows) and bacilli (open arrows) (x1000).
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However, fluid aspirated from the lung mass showed frank pus, and Gram staining of this specimen revealed Gram-positive coccobacilli and Gram-negative cocci/rods (Fig. 4).
Neighbor-joining tree of the genus Eubacteria based on 16S rRNA gene sequences.
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Subsequently, 16S rRNA gene sequencing and a phylogenetic tree analysis of the specimen (initially identified Actinomyces sp.) confirmed the presence of E. brachy (Fig. 5).