Sparganosis of Upper Extremity in Subcutaneous and Intramuscular Layers

Introduction

Sparganosis is an infection caused by sparganum, a plerocercoid larva of a cestode belonging to the genus Spirometra Spargana. Humans are the accidental, second or third intermediate host in the cestode life cycle, while dogs, cats and other mammals are definitive hosts. The parasite is typically transmitted to humans by three modes: ingestion of contaminated water, contact with raw snake or tadpoles or following the topical application of infested flesh as a poultice. Once humans become infected, the plerocercoid larvae may migrate to a subcutaneous location and produce a painful nodular lesion. Radiological and serological techniques can provide useful diagnostic clues of sparganosis.

We report a case of repeating sparganosis initially presenting as a subcutaneous mass but later manifesting as an intramuscular mass in the upper arm. This case showed the characteristic and distinctive ultrasonographic findings of sparganosis. Ultrasonographic features of sparganosis are very characteristic and distinguishable, so ultrasound imaging can be a clue for diagnosis of sparganosis.