BACKGROUND: The diagnosis of lung cancer is often made based on computed tomography (CT) image findings if it cannot be confirmed on pathological examinations, such as bronchoscopy. However, the CT image findings of cancerous lesions are similar to those of abscesses.We herein report a case of lung cancer that resembled a lung abscess on CT.

CASE REPORT: We herein describe the case of 64-year-old male who was diagnosed with lung cancer using surgery. In this case, it was quite difficult to distinguish between the lung cancer and a lung abscess on CT images, and a lung abscess was initially suspected due to symptoms, such as fever and coughing, contrast-enhanced CT image findings showing a ring-enhancing mass in the right upper lobe and the patient’s laboratory test results.However, a pathological diagnosis of lung cancer was confirmed according to the results of a rapid frozen section biopsy of the lesion.

CONCLUSIONS: This case suggests that physicians should not suspect both a lung abscesses and malignancy in cases involving masses presenting as ring-enhancing lesions on contrast-enhanced CT.

Keywords: Lung Neoplasms - etiology, Lung Neoplasms - radiography, Lung Neoplasms - surgery