Infundibular keratinizing acanthoma
Infundibular keratinizing acanthoma (intracutaneous cornifying epithelioma) are a rare epithelial benign keratin-containing neoplasia of hair follicles.
These skin tumors are characterized by peripheral proliferation of basaloid epithelial cells with differentiation to squamous epithelium resembling the normal follicular infundibulum/isthmus. The term of keratoacanthoma should be reserved for those tumors of subungual origin (nail-bed).
A typical infundibular keratinizing acanthoma consists of a well-circumscribed keratin-filled crypt in the dermis and subcutis that opens to the skin surface. Most of these tumors occur on the trunk, head, eyes and digits.
Diagnosis is based on histological examination of biopsied skin, which shows characteristic keratin filled tumor lined by large squamous cells with a pale eosinophilic cytoplasm, surrounded by a compressed dermal collagenous stroma. Some may show chondroid or osseous metaplasia.
Simple surgical excision is curative in most cases, except where additional growths develop. In these cases, multiple cryosurgery may be required with use of oral retinoids such as etretinate.
- Pets Canada
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- University of Pennsylvania
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