Pathologically confirmed pulmonary Actinomycosis in 11 cases: clinical features and misdiagnosis analysis

Abstract

Objective To analyze the pathologically confirmed pulmonary Actinomycosis in the 11 patients in focusing on clinical features and mis-diagnostic reasons so as to improve physicians' awareness of this rare disease and reduce the misdiagnosis. Methods We retrospectively reviewed the medical records of 11 cases with pathologically confirmed pulmonary Actinomycosis during January 2003-August 2015.The clinical data and main causes of misdiagnosis in these cases were collected and analyzed. Results The study included 11 patients with a mean age of(53.0±11.6.0)years.Among the 11 cases, 8(72.7%)patients had complications, 6(54.5%)were current or ex-smokers.Main clinical manifestations of 11 cases were cough(11/11, 100.0%), sputum(11/11, 100.0%), hemoptysis(7/11, 63.6%), chest pain(6/11, 54.5%)and fever(3/11, 27.3%). Ten patients presented with one lobe of lung lesions, including 4 patients in the lower lobe and 3 in the upper lobe of the left lung, 2 in the upper lobe and 1 in the lower lobe of the right lung.While, the remained one case presented with lesion locating in right main bronchus.Iconography often presented as pulmonary mass shadow, consolidation shadow, spicule sign, lobulation sign, hilar and/or mediastinal lymphadenopathy and pleural effusion.Vacuolar lesions were observed in some of the focuses.Flexible bronchoscopy was performed in 8(72.7%)patients.Among them, 7 patients showed mucosal swelling and congestion, luminal occlusion with purulence secretion, 2 cases with polypoid neoplasm.Initial misdiagnosis rate were 100%(11/11), among which 7 cases were misdiagnosed as lung cancer, 2 cases as fungus infection, and 1 case as pulmonary tuberculosis and 1 case as pneumonia, respectively.All patients were definitely diagnosed by biopsy finding an evidence of hyphae of Actinomycosis in lung tissue specimens.The definitive diagnosis was made by CT-guided percutaneous lung biopsy in 4 cases, by transbronchial lung biopsy(TBLB)in 5 cases and by thoracotomy or video-assisted thoracoscopic surgery(VATS)in 1 case respectively.Actinomycosis in most patients was cured with high-dose penicillin administration over a prolonged period. Conclusions The diagnosis of pulmonary Actinomycosis remains challenging via its non-specific clinical symptoms and iconography features, and the presence of comorbidity may further increase the difficulty and complexity of diagnosis, leading to delaying-or mistaking-diagnosis.Obtaining positively pathological specimens is diagnostic key.Transbronchial lung biopsy through a bronchoscope and CT-guided percutaneous needle biopsy are the priority methods. Key words: Actinomycosis; Diagnostic errors