A Case of Peculiar Hair Cysts Arising in the Skin of Both Postauricular Areas

Abstract

A 55-year-old woman noted progressive development of randomly scattered miliary papules involving both postauricular areas, symmetrically, over a decade. Histologically, the cysts were located in the mid-dermis and contained laminated keratinous material as well as vellus hairs. Though hair cysts do resemble primary milium, they differ from milium which usually occurs on the face and may be more superficially located in the dermis, histologically. This case was practically the same as eruptive vellus hair cysts (E. V. H. C.) located in the mid-dermis. However, precluding the diagnosis of E. V. H. C., two aspects were noted. First, the hair cysts arose in a peculiar region, not heretofore reported. Secondly, the hair cysts in this case clinically resembled milium rather than E. V. H. C.. Milia en plaque may also be considered, however, such has a predilection for the face and a tendency to aggregate to form a plaque unilaterally. This case is unique and does not fit the diagnosis as any of the above mentioned epidermal cysts.