Pilar Sheath Acanthoma


Pilar Sheath Acanthoma
Scanning magnification of a pilar sheath acanthoma shows a dilated follicular structure lined by a thickened squamous epithelium with endophytic, lobulated areas image.



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Pilar Sheath Acanthoma at Higher Magnification
Higher magnification of the lobular areas shows acanthotic squamous epithelium with peripheral palisading image and scattered clear-staining cells image.

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Pilar Sheath Acanthoma With Prominent Granular Layer
High magnification of the epithelium shows a prominent granular layer image (consistent with infundibular keratinization). The cells are mildly enlarged and squamoid appearing, with scattered pale/clear cells image.

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Pilar Sheath Acanthoma With Squamous Pearls
Foci of keratinization with squamous pearls image may be seen surrounded by bland squamoid to clear image cells.


TERMINOLOGY


Abbreviations




• Pilar sheath acanthoma (PSA)


Definitions




• Mature adnexal proliferation composed of thickened epithelium with enlarged pale-staining keratinocytes


ETIOLOGY/PATHOGENESIS


Unknown




• No known causes/associations


CLINICAL ISSUES


Epidemiology




• Incidence
image Rare lesions

• Age
image Usually occur in middle-aged to older adults

• Sex
image Males and females equally affected


Site




• Most often occur on upper lip


Presentation




• Keratotic papular lesion with central pore-like area


Natural History



Tags:
Apr 24, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Pilar Sheath Acanthoma

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