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Comedonal nevus: causes, symptoms, diagnosis, treatment
Last reviewed: 04.07.2025
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Comedonal nevus (syn.: follicular keratotic nevus) may be present from birth or appear in puberty or later in life. Clinically, comedonal nevus is represented by multiple comedones grouped in the form of ribbon-like strands of varying length or clusters of other configurations, usually unilateral localization, but bilateral variants have also been described. As a rule, the localization of the nevus is associated with the presence of hair follicles, although it rarely occurs on the scalp. Sharply dilated follicular canals of a round or oval shape contain horny substance, which is difficult to remove. The course is usually asymptomatic, but if the follicle wall is damaged, it is complicated by inflammation of varying severity.
Pathomorphology of comedonal nevus. Wide, elongated follicular canals filled with masses of keratinocytes are revealed. The epithelial lining of the funnel is usually thinned. A sharply expanded funnel can extend deep into the dermis up to the level of subcutaneous fat tissue. When the wall ruptures, a typical inflammatory reaction to a foreign body is formed.
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