Pulmonary paragonimiasis mimicking lung cancer in a tertiary referral centre in Korea

To determine how pulmonary paragonimiasis may be confused with lung cancer, we retrospectively analysed the clinical and radiological characteristics of 47 patients (27 males, median age 55 years; interquartile range 49-61) with serologically or histopathologically confirmed pulmonary paragonimiasis seen between October 2004 and December 2009.

Respiratory symptoms were present in 29 (62%) patients; the remaining 18 (38%) were asymptomatic. Chest radiography (CXR) revealed intrapulmonary parenchymal lesions (n = 35, 75%) more frequently than pleural lesions (n = 11, 23%). Of the 47 patients, 28 (60%) were referred for suspected lung cancer. The majority of these patients had no symptoms, and 22 (79%) patients with suspected lung cancer had nodular or mass lesions on CXR. As a result, additional diagnostic procedures were performed to make an accurate diagnosis in these patients, including bronchoscopy in 20, transthoracic lung biopsy in 11 and fluorodeoxyglucose positron emission tomography in seven. Surgical lung resection was performed unnecessarily in six patients.

Pulmonary paragonimiasis presenting with nodular or mass lesions on CXR is common. Clinicians should therefore include pulmonary paragonimiasis in the differential diagnosis of asymptomatic nodular lesions in the lung in patients who have lived in or travelled to paragonimiasis-endemic areas.