Pulmonary actinomycosis mimicking lung cancer on positron emission tomography

Abstract

Pulmonary actinomycosis frequently mimics lung malignancy on radiologic imaging studies. Positron emission tomography-computed tomography (PET-CT) is a useful diagnostic modality for differentiating lung malignancy from benign diseases. However, few studies evaluated PET-CT findings of pulmonary actinomycosis. Therefore, it is unclear whether PET-CT is helpful to distinguish lung malignancy from benign lung disease when pulmonary actinomycosis is clinically suspected. We investigated PET-CT findings in 11 patients with pathologically confirmed pulmonary actinomycosis. The median maximal standardized uptake value (SUV) on PET-CT of pulmonary actinomycosis was increased to 5.5 (interquartile range, 4.2–8.8), which was higher than the threshold value of 2.5 indicating malignancy. Pulmonary actinomycosis without central necrosis demonstrated higher maximal SUV of 7.5 (4.9–12.2) compared to 4.8 (3.2–5.6) of ones with central necrosis. PET-CT might be not helpful in differentiating lung malignancy from benign lesions when pulmonary actinomycosis is clinically suspected.

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

“…Frontiers in Medicine frontiersin.org airspace consolidation with low-attenuation areas that have peripheral enhancement (7,10,49). Additionally, cavitations, shadowing, and pleural effusion with cavitary lesions are also typical features of PA that can be misdiagnosed as tuberculosis (28).…”

“…The scan showed air space consolidation, mass in the middle lobes that could be misinterpreted as malignancy, pleural empyema, and opacity in the lobes, which could mimic pulmonary metastases. Moreover, positron emission tomography-computed tomography (PET-CT) is a helpful imaging technique to differentiate benign lesions from malignant ones, but there is limited information on PET-CT findings about PA (10,50). This technique was used in five cases and showed lesions and masses in lung lobes.…”

“…PA usually results in the formation of nodules, consolidation, or mass that can often be mistaken for lung cancer. Therefore, PA could be misdiagnosed as lung cancer, lung abscess, or tuberculosis (9,10). Due to non-specific laboratory and clinical features, it is usually challenging to differentiate PA from lung malignancy.…”

“…Due to non-specific laboratory and clinical features, it is usually challenging to differentiate PA from lung malignancy. Moreover, the most common initial diagnosis of PA among physicians is lung cancer (10)(11)(12)(13)(14). The common signs and symptoms of PA are fever, chest pain, hemoptysis, shortness of breath, and a productive cough (15,16).…”

Endotracheal Actinomycosis Combined with Mucormycosis: A Case Report and Literature Review

“…The lesions were frequently seen on the lungs' periphery, and most of them displayed evidence of malignant tumors when they displayed signs of mass [18][19] . Choi H et.al [20] reviewed the risk factors for pulmonary mucormycosis, describe its imaging appearance and disease process, PET-CT imaging clearly displayed increased glucose uptake, which was comparable to the symptoms of lung malignancies. The following imaging features of pulmonary mucormycosis are present [21] : (1) Single or multiple pulmonary consolidations, frequently accompanied by cavity; (2) Wedge-shaped shadow near the base of pleura; (3) single or multiple small nodules and halo sign; (4) anti-halo sign; (5) intratracheal lesions; (6) pleural effusion.…”