Pulmonary actinomycosis diagnosed by transbronchoscopic lung biopsy: A case report and literature review

An overview of case reports and case series of pulmonary actinomycosis mimicking lung cancer: a scoping review

Background

Pulmonary actinomycosis (PA) is a rare type of Actinomyces infection that can be challenging to diagnose since it often mimics lung cancer.

Methods

Published case reports and case series of PA in patients with suspicion of lung cancer were considered, and data were extracted by a structured search through PubMed/Medline.

Results

After analyzing Medline, 31 studies were reviewed, from which 48 cases were extracted. Europe had the highest prevalence of reported cases with 45.1%, followed by Asia (32.2%), America (19.3%), and Africa (3.2%). The average age of patients was 58.9 years, and 75% of all patients were above 50 years old. Male patients (70%) were predominantly affected by PA. The overall mortality rate was 6.25%. In only eight cases, the causative agent was reported, and Actinomyces odontolyticus was the most common isolated pathogen with three cases. Based on histopathological examination, 75% of the cases were diagnosed, and the lobectomy was performed in 10 cases, the most common surgical intervention. In 50% of the cases, the selective antibiotics were intravenous and oral penicillin, followed by amoxicillin (29.1%), amoxicillin-clavulanic acid, ampicillin, levofloxacin, and doxycycline.

Conclusion

The non-specific symptoms resemble lung cancer, leading to confusion between PA and cancer in imaging scans. Radiological techniques are helpful but have limitations that can lead to unnecessary surgeries when confusing PA with lung cancer. Therefore, it is important to raise awareness about the signs and symptoms of PA and lung cancer to prevent undesirable complications and ensure appropriate treatment measures are taken.

Pulmonary Actinomycosis: A Diagnostic Challenge

Pulmonary actinomycosis is an uncommon and challenging infectious disease with non-specific symptoms and imaging findings. The authors report a case of a 68-year-old man with diabetes and a history of past smoking who presented with anorexia and weight loss with no significant findings on physical examination. A parenchymal consolidation in the anterior segment of the right upper lobe was detected after a chest computed tomography (CT). Bacterial colonies of Actinomyces species were identified in the histology of transbronchial biopsy. Imaging reassessment after six weeks of treatment with oral amoxicillin showed progression with a high metabolism 10.5 standardized uptake value (SUV) documented on the f-fluorodeoxyglucose positron emission tomography/CT. Concern about the possibility of lung cancer was raised and ruled out by a negative transthoracic needle biopsy. The diagnosis of pulmonary actinomycosis with pyogenic superinfection was presumed. The patient was successfully treated with intravenous amoxicillin and clavulanate for two weeks, followed by six months of oral treatment.

Pulmonary invasive mucinous adenocarcinoma mimicking pulmonary actinomycosis

Background

Primary pulmonary invasive mucinous adenocarcinoma is a rare and distinct subtype of lung adenocarcinoma.

Case presentation

A 72-year-old woman presented with productive cough for two months and fever for six days. Chest computed tomography (CT) showed a mass in the left lower lobe. Sputum culture tested negative for bacteria, but the sequence of Actinomyces meyeri was detected by metagenomic next generation sequencing from the bronchoalveolar lavage fluid. It was considered a pathogenic bacterium as the normalized number of DNA sequencing reads was 10 times higher than the normal level. The patient’s symptoms alleviated quickly, and the chest CT lesion shrank to a third of the original size following treatment with penicillin for two months. However, a repeat chest CT performed after four months of treatment revealed that the lesion had expanded. Positron emission tomography/CT revealed that fluorodeoxyglucose metabolism was increased in the mass with surrounding ground glass density of the left lower lobe. Furthermore, CT-guided percutaneous lung biopsy was performed, and hematoxylin–eosin staining showed columnar tumor cells with abundant mucin in the cytoplasm with a basal nucleus. Finally, the patient was diagnosed with pulmonary invasive mucinous adenocarcinoma and agreed to undergo a thoracoscopic surgery.

Conclusions

Pulmonary invasive mucinous adenocarcinoma is a subset of lung adenocarcinoma with low incidence rate. The clinical features and CT findings are non-specific. A histopathological diagnosis is of fundamental importance in preventing misdiagnosis.

Pulmonary Actinomycosis Revealed by a Solitary Pulmonary Nodule

Background

Pulmonary actinomycosis (PA) is a rare and ubiquitous bacterial disorder, combining subacute or chronic focal suppuration and an expansive fibrogranulomatous lesion. Lung involvement is rare. The radioclinical manifestations of this infection are polymorphic and confusing. The form revealed by a solitary pulmonary nodule is exceptional and not documented in the literature. Case Presentation. We report a case of a 71-year-old patient, 25-year package smoker, revealed by repeated moderate-abundance hemoptysis with a rare radiological image: in the form of a solitary pulmonary nodule located at the left chest base. The negativity of bacteriological research, endoscopic samples, the failure of treatment of the bleeding by medical and embolization, and at last the suspicion of a neoplasia led us to perform a thoracotomy for diagnostic and therapeutic purposes. This surgery highlighted evidence of filamentous basophilic grains posing the diagnosis of PA. Appropriate treatment allowed a cure without recurrence after 02 years of follow-up.

Conclusion

Pulmonary actinomycosis can be revealed by different radiological forms. Pulmonary actinomycosis should be considered in the presence of any solitary lung nodule in order to reduce the morbidity and cost associated with thoracotomy.

A Rare Bug and Recurrent Bleed

Isolated pulmonary actinomycosis is a rare entity. Its clinical features and radiological findings are nonspecific, making early diagnosis difficult for clinicians. We report a case of 40-year-old nonsmoker, immunocompetent male without an underlying structural lung disease who presented to us with recurrent hemoptysis and was diagnosed to have Actinomycosis after multiple readmissions.