Dilated Pore of Winer
Dilated pore of Winer (DPW) is a benign growth belonging to the group of skin adnexal tumors. It arises from abnormal differentiation and widening of the upper part of the hair follicle (the follicular infundibulum). It usually appears as a single large opening filled with a dark brown or black keratin plug, much like a giant blackhead (giant comedo). DPW occurs mainly on the face, neck and trunk of older adults. Although it never becomes malignant, it does not go away on its own and is easily inflamed or left with a deep pitted scar when people squeeze it or have it treated with improper technique.
At Haute-Derma, we offer specialized treatment grounded in the microscopic pathology of the lesion, combining minimally invasive surgery with aesthetic tissue repair to remove the overgrown follicle sac completely and restore a smooth, natural skin surface.
Causes and Clinical Features
- How it forms: DPW results from chronic blockage and overgrowth of the lining of the follicular infundibulum. Shed keratin cells accumulate inside the widened follicle, forming a dense, uniform plug that seals its opening.
- Clinical appearance: a round or oval opening 2 mm to more than 10 mm across, with a hard black keratin plug in the center. It is not painful to press (unless secondarily infected). If the plug is squeezed out, the opening remains and quickly fills with new keratin.
Microscopic Features (Histopathology)
- Ectatic infundibulum: the follicular infundibulum is greatly widened into a jar- or deep cup-shaped cavity that extends into the superficial and mid dermis and is filled with layers of lamellated keratin.
- Acanthotic (radiating) projections: the most distinctive histologic feature of DPW is found in the lower wall and base of the cavity. Here the epithelium is not thinned; instead it sends finger-like rete ridges outward into the surrounding dermal stroma.
- Stroma and cells: there is no cellular atypia, abnormal mitosis or invasion. The fibrous stroma around the cavity is often compressed but shows no granulomatous inflammation unless the wall has ruptured from external trauma.
Differential Diagnosis and Immunohistochemistry (IHC)
| Condition | Distinguishing microscopic features | Immunohistochemistry / clinical criteria |
|---|---|---|
| Dilated pore of Winer (DPW) | Widened infundibulum filled with lamellated keratin, with finger-like epithelial projections at the base. | CD34 (+) in the stroma around the projections; very low Ki-67 (< 1%), confined to the basal layer. |
| Giant comedo | Widened, keratin-filled infundibulum, but with a thinned epithelial wall and no epithelial projections at the base. | Distinguished mainly on H&E microscopy. |
| Epidermoid cyst | Closed cyst deep in the dermis/subcutis, lined by all normal epidermal layers (prominent granular layer). | Usually lacks the wide surface opening seen in DPW. |
| Trichofolliculoma | Widened central follicle with many small secondary (daughter) follicles radiating from it at various stages of differentiation. | CK20 (+) Merkel cells within the secondary follicles. |
Our Approach to Treating Dilated Pore of Winer
Led by our dermatologists, Haute-Derma removes DPW completely while preserving the best possible cosmetic result:
- Accurate screening and microscopic assessment: clearly distinguishing DPW from other adnexal cysts or from keratinizing precancerous lesions.
- Complete removal of the follicle sac (complete capsule elimination): we remove not only the keratin plug but also the overgrown epithelial wall at the base of the cavity, so the lesion does not come back.
- A tailored technique: punch excision, fractional CO2 laser ablation or cosmetic suture closure, depending on the size of the opening.
- Repair and pore tightening: combined with collagen-remodeling treatment to fill the tissue defect left after the cyst is removed.
How We Diagnose Dilated Pore of Winer at Haute-Derma
Our standardized diagnostic process accurately assesses the depth and features of the lesion:
- Clinical examination and dermoscopy: we look at the central keratin plug, the diameter of the opening and the pattern of blood vessels around the edge.
- Medical history: how long the lesion has been present, how often the plug has been squeezed or extracted, and any repeated episodes of inflammation.
- Biopsy and histopathology (when needed): for lesions with an unusual appearance, a slightly firm edge, or suspicion of morpheaform or keratotic basal cell carcinoma.
- Planning the procedure: choosing between punch excision and laser, and planning the closure along the relaxed skin tension lines (RSTL).
Specialized Treatment at Haute-Derma
Our treatment plan addresses the root cause of dilated pore of Winer:
- Punch excision and primary cosmetic closure:
- Used for medium and large lesions (> 3 mm).
- A punch sized to fit the lesion exactly removes the keratin plug together with the entire overgrown epithelial wall at the base.
- The wound is closed in two layers (subcutaneous and epidermal) with ultrafine sutures, turning the large opening into a fine line that follows the skin creases.
- Ultrapulse CO2 laser ablation and electrosurgery of the base:
- Used for small lesions (< 3 mm) in sites that are difficult to operate on.
- The CO2 laser is fine-tuned to vaporize the keratin plug and precisely destroy the overgrown epithelial wall without spreading heat damage to healthy tissue.
- Regenerative treatment to fill the tissue defect:
- Growth factors (EGF/FGF) are applied and red/near-infrared LED light therapy is given right after the procedure to stimulate collagen that fills the base of the defect.
- Aftercare and scar management: a dedicated scar cream, with a follow-up visit after 1–2 weeks to check healing.
