Author: Dr Ben Tallon, Dermatologist/Dermatopathologist, Tauranga, New Zealand, 2012.
This lesion falls within the group of benignfollicular tumours.
Histology of dilated pore of Winer
Scanning power view of dilated pore of Winer demonstrates a small invaginating epidermal process (Figure 1). This is comprised of a widened follicularinfundibulum filled with a small amount of keratinous material (Figure 2). The infundibularepithelium is hyperplastic, forming small radiating strands at the base and sides of the pore (Figure 2).
Pilar sheath acanthoma: In this lesion there is more prominent hyperplasia of the outer root sheath forming tumournodules which push into the surrounding dermis. This tumour arises from the follicular isthmus where the corneocytes take on a more red-pink colour.
Trichofolliculoma: Radiating hairfollicles in variable states of maturity are seen to extend from the central dilated pore or cystic structure.
Hair cortex comedo : This lesion demonstrates infundibularepithelium associated with a dense cornified plug with compact laminated corneocytes, and matrical and supramatrical epithelium representing attempts to form the hair cortex and shaft.