A case of giant subcutaneous dermoid cyst of the right shoulder

Abstract

We describe a 16-year-old man suffering from a giant subcutaneous dermoid cyst. The patient presented a subcutaneous nodule on the right shoulder that he had had since birth, which gradually grew into a mass with the size of a chicken egg. The tumor could be removed easily from underling tissues and had fistula on the surface of the mass, from which several hair shafts projected. Contrast-enhanced computed tomography revealed a 86×44×67 mm well circumscribed low density unilocular cyst on the upper-dorsal aspect of the right scapula. The resected tumor displayed a fibrous connected tissue capsule that contained hair and atheromatous substance. A diagnosis of subcutaneous dermoid cyst was established based on the histopathological findings represented by a cyst lined by stratified squamous epithelium with hair follicles, sebaceous glands and smooth muscle. No recurrence had been observed for 20 months after the operation. Most subcutaneous dermoid cysts appear in the region of the head and neck, but rarely in other regions. Only 7 cases of subcutaneous dermoid cysts with diameters of more than 5 cm have been reported in Japan. Among these 7 cases, our case was the only one with the cyst observed in a region other than head and neck.