Linear nevus comedonicus with epidermolytic hyperkeratosis.

Background: Nevus comedonicus (NC) is rarely associated with the histopathologic pattern of follicular epidermolytic hyperkeratosis (EHK). We found eight cases reported. In one case, the condition was transmitted to the offspring in the form of generalized EHK.

Methods: We describe a case of linear NC with EHK in a 46-year-old woman.

Results: Histopathologic examination revealed the typical features of NC. Additionally, the follicular epithelial walls showed EHK with characteristic perinuclear vacuolization in the stratum spinosum and stratum granulosum and large, irregular keratohyalin granules in the granular cell layer.

Conclusions: The clinical and histopathologic features of this case are consistent with a diagnosis of linear NC with EHK. Lesions of NC suspected by clinical exam should be examined microscopically to look for features of EHK. If present, patients should be educated about the risk, albeit rare, of passing on a more severe form of the disorder to subsequent generations.