Hybrid cysts showing alternate combination of eruptive vellus hair cyst, steatocystoma multiplex, and epidermoid cyst, and an association among the three conditions.

Eruptive vellus hair cyst (EVHC), steatocystoma multiplex (SM), and epidermoid cyst are characterized by formation of multiple cutaneous cysts and have a resemblance in clinical features but have distinctive histologic features. We present herein two patients, who had EVHC, SM, and EVHC with sebaceous gland, and who also had EVHC, SM, and epidermoid cyst with sebaceous gland and vellus hairs. In addition, the interrelation among the three diseases is discussed. We think that EVHC, SM and epidermoid cyst are within the same spectrum of the disease process.