Sparganum mansoni parasitic infection in the lung showing a nodule.

Reported herein is a 57-year-old man infected by Sparganum mansoni, a kind of tapeworm, showing a solitary nodule of the middle lobe of the right lung. Because a transbronchial biopsy could not diagnose the nodule, a right middle lobectomy was performed on suspicion of malignant tumor. The lesion was diagnosed as sparganosis by histological and immuno-serological examinations. Histological examination revealed granulomatous inflammation with neutrophil and eosinophil infiltration around the worm and interstitial pneumonia surrounding the nodule. Moreover, vasculitis with foreign body giant cell was seen around the lesion. To the authors' knowledge this is the second case of sparganosis limited in the lung, and the current report presents the first detailed histological description of a pulmonary sparganosis case.