2018 Volume 32 Issue 5 Pages 580-586
Pulmonary paragonimiasis westermani is a relatively rare cause of lung disease with a wide variety of radiologic findings, such as air-space consolidation, nodules, and cysts. Here, we describe a case of pulmonary P. westermani in a 51-year-old man who presented with a persistent cough. A chest radiograph showed a pulmonary nodular shadow in the left middle lung field. When he underwent a check-up at our hospital about a year later, the nodular shadow had increased in size. Chest computed tomography (CT) showed a nodular lesion with a maximal diameter of 40 mm in S4 of the left upper lobe. The pulmonary nodular lesion invaded the adjacent lobe across the interlobar pleura. 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) CT images showed abnormally intense uptake with a standardized uptake volume (SUV) of 10.3 in the left pulmonary lesion, and 2.6 in the left hilar lymph nodes. A specimen obtained by transthoracic computed tomography-guided core needle biopsy (TTNB) showed lymphocytic interstitial pneumonia. Based on chest CT and FDG-PET findings, we could not rule out the possibility of primary lung cancer. He underwent lingulectomy with a partial resection of the left lower lobe. Histological examination of a paraffin section showed a large number of parasite eggs and infiltration of eosinophils with an associated granulomatous reaction. In a postoperative enzyme-linked immunosorbent assay (ELISA), the patient's serum strongly reacted to P. westermani antigen. Based on these findings, the patient was diagnosed with pulmonary P. westermani infection. Following confirmation of the diagnosis, he received praziquantel therapy at 75 mg/kg orally for 3 days. In Japan, paragonimiasis is recently rarely reported; however, P. westermani infection should be considered when abnormal shadows are found on a chest radiopraph and chest CT.
