Soft tissue sparganosis

ABSTRACT

Sparganosis is a rare tissue-parasitic infestation caused by a plerocercoid tapeworm larva(sparganum), genus Spirometra. The most common clinical presentation of sparganosis is a palpable subcutaneous mass or masses. Fifteen simple radiographs and 10 ultrasonograms of 17 patients with operatively verified subcutaneous sparganosis were retrospectively analyzed to find its radiologic characteristics for preoperative diagnosis of sparganosis. The locations of the subcutaneous sparganosis were lower extremity, abdominal wall, breast, inguinal region and scrotum in order of frequency. The simple radiographs showed linear or elongated calcification with or without nodular elongated shaped soft tissue mass shadows in 8 patients, soft tissue mass shadow only in 2 patients and lateral abdominal wall thickening in 1 patient. But no specific findings was noted in 4 patients with small abdominal and inguinal masses. We could classify the subcutaneous sparganosis by ultrasound into 2 types one is long band-like hypoechoic structures, corresponding to the subcutaneous tunnel-like tracks formed by migration of sparganum larva and the other is elongated or ovoid hypoechoic nodules, representing granulomas. Long band-like hypoechoic structures within or associated with mixed echoic granulomatous masses were noted in 6 patients and elongated or ovoid hypoechoic mass or masses were noted in 4 patients. In conclusion, sparganosis should be considered when these radiologic findings-irregular linear calcifications on simple radiograph and long ban-like hypoechoic structures on ultrasonography, corresponding to the subcutaneous tunnel-like tracks formed by migration of sparganum larva-are noted in the patients who have subcutaneous palpable mass or masses. And radiologic examination especially ultrasonography is very helpful to diagnose sparganosis.