Large Ganglion Cyst with Unusual Location on the Back-A Case Report

Abstract

A ganglion cyst is a soft tissue tumor-like lesion filled with colloid material commonly located on the hand and wrist. We report a case of a large ganglion cyst with an unusual location on the back. The patient presented with a mass growing over 2 months measuring 11.2 × 4.7 × 7.2 cm on magnetic resonance imaging. Ultrasound and puncture was attempted twice without achieving drainage. After surgical removal, histologic examination diagnosed the tumor as a ganglion cyst. We conclude that when evaluating a subcutaneous soft tissue mass, regardless of localization, a ganglion cyst may be a differential diagnosis.

Fig. 1.

Clinical presentation of the large ganglion cyst from a posterior aspect.

Fig. 2.

MRI of the thorax showing the ganglion cyst (indicated by arrows).

Fig. 3.

Microscopic images of the ganglion cyst wall. A, hematoxylin and eosin stain, ×100. B, Alcian blue/Sirius red, ×100. C, CD68, KP1, and immunostaining for histiocytic cells, ×100. D, Close-up view of the inner lining of the cyst with CD68-positive cells, corresponding to the content of the framed area in (C). CD68, KP1, and immunostaining, ×400.