Eruptive vellus hair cysts. A follicular cyst of the sebaceous duct (sometimes).

The eruptive vellus hair cyst is an uncommon, yet distinct, clinical and pathological entity that may be acquired in a sporadic or hereditary form. This descriptive term gives no indication of the type of epithelium lining this cyst. A case report of eruptive vellus hair cyst is reported herein in which the epithelial lining differentiated toward the sebaceous duct. We propose that eruptive vellus hair cysts should be more accurately diagnosed by characterizing the type of epithelial lining.