Pathology of Clear Cell Acanthoma  

"Skin lesion with enlarged pale stained keratinocytes" 

Dr Sampurna Roy MD        2022

Clear cell acanthoma (pale cell acanthoma) is a discrete idiopathic psoriasiform lesion of large pale staining, non-keratinizing, glycogenated, monomorphous keratinocytes associated with neutrophils. The lesion is separated from the adjacent epidermis.

(Dermatopathology Poster )

It was first described by Degos et al in 1962.

Clinical presentation:  Presents as a firm brown-red dome shaped nodule or papule.

The lesion is usually between 5 to 10 mm or more in diameter. 

Clear cell acanthoma is usually solitary but can be multiple.

Clinical bleeding is rare.

The surface of the lesion may be smooth to bosellated and crusted.

Age:  Middle aged and elderly individuals. Some cases have been reported in younger patients.

Site: Commonly located on the lower limbs. These may also be found on the trunk and face.

Immunohistochemistry:  The cells contain cytokeratin and involucrin but not carcinoembryonic antigen.

Differential diagnosis: Eccrine poroma ; Trichilemmoma ; Psoriasis; Clonal type-Seborrheic keratosis ; Verruca vulgaris  

Dermatopathology Case No 25

Clear cell acanthoma with changes of eccrine syringofibroadenoma: reactive change or clue to etiology?

Multiple clear-cell acanthomas.

Clinicopathologic and immunohistochemical studies of conjunctival large cell acanthoma, epidermoid dysplasia, and squamous papilloma.

Clear cell acanthoma of the areola and nipple: clinical, histopathological, and immunohistochemical features of two Brazilian cases.

Clear cell acanthoma.

Clear cell acanthoma induced by a dermatofibroma.

Hemosiderotic clear-cell acanthoma: a pigmented mimicker.

Clear cell acanthoma: a rare clinical diagnosis prior to biopsy.

A case of polypoid clear cell acanthoma on the nipple.

Clear (pale) cell acanthosis as an incidental finding.

A case of polypoid clear cell acanthoma on the scrotum.

Polypoid clear cell acanthoma of the scalp.

Clear cell acanthoma presenting as polypoid papule combined with melanocytic nevus.