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Benign epidermal tumorsBenign epidermal tumors

Deba P Sarma, MDDeba P Sarma, MD

OmahaOmaha

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EpidermisEpidermis

1. Basket-weave keratin

2. Granular keratinocytes

3. Maturing keratinocytes

4. Cuboidal basal cells with melanocytes

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4

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Benign tumors from epidermalBenign tumors from epidermalcells(Keratinocytes)cells(Keratinocytes)

Epidermal nevusEpidermal nevus

AcanthomaAcanthoma

a. Seborrheic keratosisa. Seborrheic keratosis

b. Large cell acanthomab. Large cell acanthomac. Clear cell acanthomac. Clear cell acanthoma

d. Acantholytic acanthomad. Acantholytic acanthoma

e. Epidermolytic acanthomae. Epidermolytic acanthoma

f. Warty dyskeratomaf. Warty dyskeratoma

g. Pseudoepitheliomatous epidermal hyperplasiag. Pseudoepitheliomatous epidermal hyperplasia

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Epidermal nevusEpidermal nevus

Clinical:

-Verrucous papule at birth, early childhood.

-Solitary, clustered or linear on the trunk.

Pathology:

-Hyperkeratosis, acanthosis, papillomatosis.

-Regular church-spired or flat topped

(mesa)

papillomatosis.

-Rarely, acantholysis and dyskeratosis.

Church-spireMesa

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AcanthomaAcanthoma

Benign neoplasm of the acanthocytes (keratinocytes)Benign neoplasm of the acanthocytes (keratinocytes)

Acanthocytes + oma = AcanthomaAcanthocytes + oma = Acanthoma

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Seborrheic keratosisSeborrheic keratosis

Clinical:

Rough-surfaced papule, nodule, or plaque.

Common lesion after 40, any part of the body except palm and sole.Pathology:

Stuck-on, sharply demarcated raised lesion with a straight line at base.

Hyperkeratosis, acanthosis, papillomatosis, basaloid epidermal cells, pseudohorn

cysts with keratin.

Variations:Acanthotic, hyperkeratotic, reticulated, pigmented, clonal, irritated, and

inverted follicular keratosis.

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Large cell acanthomaLarge cell acanthoma

Clinical: Middle aged or older adults.

-Sharply demarcated patch on head and neck, trunk and limbs.

Pathology:

-Basket-weave hyperkeratosis, hypergranulosis, flat-topped papillomatosis and rounded

acanthosis.

-The keratinocyres of the lesion are larger with larger nuclei compared to

the adjacent epidermis.

-The lesion is sharply demarcated from the adjacent epidermis.

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Clear cell acanthoma (Pale cell acanthoma)Clear cell acanthoma (Pale cell acanthoma)

Clinical:Adults,> 40, leg

Pathology:

-Acanthotic epidermis is sharply demarcated from adjacent epidermis

-Composed of pale or clear keratinocytes with focal neutrophils (inset)