A Case of Multiple Pilosebaceous Cysts.

Multiple pilosebaceous cysts include the entities of steatocystoma multiplex and eruptive vellus hair cysts (EVHCs). Multiple pilosebaceous cysts are proposed to be one entity originating in the pilosebaceous duct, since steatocystoma multiplex and EVHCs are frequently present concomitantly and are caused by a cystic change in the same pilosebaceous duct. Here, we describe a patient with yellowish papules, 3-8 mm in diameter, on the neck and skin-colored or light-brown papules, 1-3 mm in diameter, on the neck, chest and upper abdomen. The smaller cysts were histopathologically diagnosed as EVHCs. The larger cysts had both features of EVHCs and steatocystoma multiplex. Therefore, a diagnosis of these lesions was made as multiple pilosebaceous cysts. Our case supports the proposition that multiple pilosebaceous cysts are a more appropriate diagnosis than the terms of EVHCs and steatocystoma multiplex.