A Case of Paragonimiasis that was Suspicious for a Lung Malignancy by PET/CT

A Case of Delayed Diagnosis of Pulmonary Paragonimiasis due to Improvement after Anti-tuberculosis Therapy

Here, we report a case of pulmonary paragonimiasis that was improved with initial anti-tuberculosis (TB) therapy but confused with reactivated pulmonary TB. A 53-year-old Chinese female presented with a persistent productive cough with foul smelling phlegm and blood streaked sputum. Radiologic findings showed subpleural cavitary consolidation in the right upper lobe (RUL). Bronchoscopic and cytological examination showed no remarkable medical feature. She was diagnosed with smear-negative TB, and her radiologic findings improved after receiving a 6-month anti-TB therapy. The chest CT scans, however, obtained at 4 months after completion of anti-TB therapy showed a newly developed subpleural consolidation in the RUL. She refused pathologic confirmation and was re-treated with anti-TB medication. Nevertheless, her chest CT scans revealed newly developed cavitary nodules at 5 months after re-treatment. She underwent thoracoscopic wedge resection; the pathological examination reported that granuloma caused by Paragonimus westermani. Paragonimiasis should also be considered in patients assessed with smear-negative pulmonary TB.

A pulmonary paragonimiasis case mimicking metastatic pulmonary tumor

Pulmonary paragonimiasis is a relatively rare cause of lung disease revealing a wide variety of radiologic findings, such as air-space consolidation, nodules, and cysts. We describe here a case of pulmonary paragonimiasis in a 27-year-old woman who presented with a 2-month history of cough and sputum. Based on chest computed tomography (CT) scans and fluorodeoxyglucose positron emission tomography (FDG-PET) findings, the patient was suspected to have a metastatic lung tumor. However, she was diagnosed as having Paragonimus westermani infection by an immunoserological examination using ELISA. Follow-up chest X-ray and CT scans after chemotherapy with praziquantel showed an obvious improvement. There have been several reported cases of pulmonary paragonimiasis mimicking lung tumors on FDG-PET. However, all of them were suspected as primary lung tumors. To our knowledge, this patient represents the first case of paragonimiasis mimicking metastatic lung disease on FDG-PET CT imaging.