Abstract
In a 2-year-old girl, a well-defined tumor of 2×2 cm in size was palpated on the outside of the middle part of the left upper arm. CT revealed a round low density area with a uniform internal structure. The tumor was in no contact with the fascia, had no so-called peduncle, and could be easily extirpated. Preoperative definite diagnosis could not be made and based on pathological findings the tumor was diagnosed as ganglion. In this case no possible structural origin nor etiologic mechanism could be inferred.
In the diagnosis of tumors in the soft parts, CT scan appears valuable in exploring the site, size, and characteristics of the tumors. There was no report describing a ganglion in fatty tissues of the upper arm in the Japanese literature, and this case is extremely rare.
