Case of subcutaneous sparganosis: use of imaging in definitive preoperative diagnosis.

Herein, we report a rare case of subcutaneous sparganosis in a 60-year-old Japanese woman. She had a 2 cm x 2 cm elastic-hard, subcutaneous nodule, which was the larva of a tapeworm, and a surrounding granuloma in her internal thigh. It was thought that she became infected by drinking water contaminated with the worm. She was definitively diagnosed by enzyme-linked immunosorbent assay (ELISA). After excision of the lesion, the titer of ELISA showed clear decline; therefore, we could conclude that she had been completely freed from sparganosis. The magnetic resonance imaging (MRI) and ultrasound sonography of her subcutaneous nodule demonstrated the characteristic signs: a band-like structure in the MRI and a coiled linear hypoechoic body in a clear, oval mass in the ultrasound sonography.