Benign epidermal neoplasms Flashcards

Question

Hyperkeratotic seb k histology

Answer 1

Prominent hyperkeratosis and papillomatosis - 'church spires' Squamous cells >> basaloid cells Not much pigment Less pseudocysts

Answer 2

Delicate strands of epithelium that extend from the epidermis in an interlacing pattern Double row or more of basaloid cells that may be hyperpigmented Horn pseudocysts may be present Solar lentigo often seen at lateral margins

Answer 3

Lymphoid infiltrate - can be perivascular, diffuse or licehnoid Spongiosis Keratinocyte necrosis Squamous eddies are common - whorls of eosinophilic keratinocytes Often lack the sharply demarcated horizontal base seen with most seb ks

Answer 4

Well defined nests of loosely packed cells within the epithelium Nests are composed of variably sized kerastinocytes that are paler than adjacent cells and have a uniform appearance May also contain melanocytes Can have Borst-Jadassohn phenomenon: intraepidermal epithelioma - you see this with eccrine poroma and other intraepidermal sweat glands, Bowens

Answer 5

Seb k that mimics MIS | Negative for Melan-A/MART-1 and S100

Answer 6

DPN Stucco keratosis Inverted follicular keratoses

Answer 7

Yes: over time the buds of pigmented basaloid cells become thicker and there is greater acanthosis

Answer 8

Heavily pigmented: keratincoytes contain the nulk of pigment (have long dendrites), and there are melanocytes distributed throughout the lesion The heavy pigmentation is explained by the blockage of transfer of melanin to keratinocytes - resulting in an increase in the amount of melanin within melanocytes Different to a seb k, is a ddx for melanoacanthoma seb k Histo: minimal epidermal hyperplasia, look more like a heavily pigmented lentigo simplex with a proliferation of dendritic melanocytes within the basal layer of the epithelium

Answer 9

1. The variants: DPN, stucco keratosis, inverted follicular keratoses 2. Other benign epidermal and melanocytic neoplasms: - solar lentigo - acrochordon - melanocytic naevus - tumour of the follicular infundibulum - superficial distinct plate-like epithelial proliferation - multiple slender epidermal connections composed of basaloid or pale cells - eccrine poroma (for acanthotic and iritated --> poromas are homogenous, small basophilic cells with delicate fibrovascular stroma and narrow ductal lumina with eosinophilic, PAS-positive, diastase resistant cuticles) - melanoacanthoma - AN - epidermal naevus - CARP - acrokeratosis verruciformis of Hopf - acanthoma fissuratum (epidermal hyperplasia due to friction) 3. Malignancies: - Bowen disease (can have Borst Jadassohn phenomenon) - SCC - melanoma (particulary verrucous) 4. Infectious: - verruca vulgaris - condyloma accuminatum

Answer 10

``` LN2 C&C/shave Electrodessication Laser: Erb:Yag AKT inhibitors - possible future topical therapy ```

Answer 11

Inflammation of solar lentigo, ak or seb k | Lichenoid infiltrate of lymphocytes secondary to a stimulus from an unidentified epidermal antigen

Answer 12

Forearm and upper chest, less frequent occurrence on shins and other chronically sun exposed sites

Answer 13

Light brown pseudonetworks due to residual solar lentigo Overlapping pinkish areas due to lichenoid inflammation Annular granular structures and gray pseudonetworks in the early regressing stage White blue-gray fine dots can be seen in the late regressing stage Blue-gray dots or globules - representing melanophages - are also considered typical of an LK

Answer 14

1. Lichenoid change: lymphocytes with scattered histiocytes, +/- eos and plasma cells, full interface dermatitis - basal vacuolar alteration, melanin incontinence, colloid bodies (if ++ melanin incontinence can be called pigmented LK) 2. Epidermal changes: can have parakeratosis, can have frank separation of epidermis from the infiltrate in the dermis --> sub-epidermal cleft or blister cavity 3. Changes of solar lentigo or macular seb k present at periphery of specimen 4. Regression - can undergo, loosely fibrotic papillary dermis with scattered lymphocytes and melanophages. Can be confused for a melanoma, but a regressed melanoma will have a dense band of melanophages with lymphocytes and dilated blood vessels, with thin epidermis 5. Mimicks MF (Pautrier like microabscesses, alignment of lymphocytes along the basal layer, epidermotropism) and lupus (atrophic variant)

Answer 15

Half present at birth Others appear in childhood, usually before age 10 Adulthood is rare and associated with irritation or trauma

Answer 16

Growth dysregulation affecting the mesodermal portion of the pilosebaceous unit NEK9 (NIMA related kinase 9 gene) has been identified as mosaic activating mutation

Answer 17

Has FGFR2 mutation - has pre-existing linear hypopigmentation, peripubertal onset of acne, and histo shows an atrophic comedonal wall with prominent associated sebaceous lobules

Answer 18

Yes very rare reports of SCC or KA

Answer 19

Face most commonly, then trunk, neck, upper extremity Can also occur on palms, soles, glans penis Elbows and knees: can be verrucous in appearance Worsens with hormones

Answer 20

Rare autosomal dominant disorder in which comedones arise during childhood or adolescece Widely scattered to trunk and extremities No linear configuration

Answer 21

``` Infantile acne Chloracne Familial dyskeratotic comedones Dilated pore naevus Porokeratotic eccrine ostial and dermal duct naevi ```

Answer 22

``` Obesity Menstrual irregularities DM Pituitary disorders Thyroid disorders ```

Answer 23

1. ?Malassezia furfur response 2. ?Insulin resistance 3. Keratinization disorder

Answer 24

Hyperkeratosis Acanthosis Papillomatosis Sparse, superficial perivascular infiltrates of lymphocytes 'Dirty feet': club-shaped, bulbous epidermal rete ridges that protrude slightly into the papillary dermis with pigment at their bases

Answer 25

AN Tinea versicolor Darier Retention hyperkeratosis Histo: seb k, epidermal naevus, AN, papillomatous epithelial proliferation

Answer 26

Chinese and other Asian children

Answer 27

Milk lines (mammary ridge)

Answer 28

? benign extra mammary Paget disease | Clear cells in lesional skin suggests histogenic relationship with Toker cells

Answer 29

Multiple white macules or papules 2-10 mm in diameter that favour the anterior chest, abdomen and lumbar region, and milk lines Rarely the face

Answer 30

Mild acanthosis Slightly disorganized arrangement of epidermal keratinocytes Numerous clear cells scattered primarily along the basal layer of the epidermis but also within its upper layers Cells have ++ mucin in their cytoplasm Stain with PAS, ALcian blue, mucicarmine, colloidal iron Immunohistochemistry: clear cells express CEA, cytokeratins: CK7, AE1/3, CAM5.2, EMA, gross cystic disease fluid protein Negative for CD1a, S100 and HMB45 Histologically looks like Paget disease