Winer's dilated pore: the infundibuloma.

This article summarizes Louis H. Winer's description of the dilated pore and some of the pertinent literature about the dilated pore. To better understand the discussion that follows, there is a brief review of the histology of the follicular infundibulum and isthmus, then a discussion of the architectural and cytologic differentiation of proliferations that reputedly differentiate toward the infundibulum. These other proliferations with their original photomicrographs are discussed rather extensively to support the argument that they do not differentiate either architecturally or cellularly toward the infundibulum. I then present evidence that contradicts those authors who claim that Winer's dilated pore is only a cyst and conclude that it is a neoplasm sui generis and the only neoplasm of the skin that differentiates architecturally and cytologically towards the infundibulum (the infundibuloma).