Unusual Eyelid Dermal Keratinous Cysts of Pilosebaceous Origin

The study described two previously unrecognized types of dermal keratinous cysts of the eyelids: sebaceous duct cysts from the glands of Zeis and multiple eruptive vellus hair cysts. Four patients were examined, with two having solitary sebaceous duct cysts and two having clusters of small papules. Histopathologic and immunohistochemical analyses revealed distinct characteristics for each type, differentiating them from common keratinous epidermoid cysts. Sebaceous duct cysts were treated effectively with local excision, while vellus hair cysts were more resistant to treatment. Both types were unrelated to deeper Meibomian keratinous cysts.