Basal: 1 cell thick w/ rest in BM (1 melanocyte to 10 basal keratinocytes)

Spinous: X cells thick and is most of epidermis

Granular: keratinocytes w/ keratohyaline granules

Corneal: dead, flattened keratinocytes

melanocyte proliferation, incr risk melanoma, premalignant lesion, complete excision recommended

-Histo: architectural changes, cytologic atypia, stromal response

What is the Px factor for melanoma?

What else is significant?

What does staging include?

- Depth of invasion (Breslow thickness) is most impt Px factor: >4mm deep have hi chance of metastasis

-Ulceration is also sig

-Staging incld: depth, ulceration, metastasis

V. common, middle aged, older; brown plaques, well demarcated, stuck on skin

-histo: proliferation of keratinocytes that often show hyperkeratosis and horn cysts; No relation to sebaceous gland

Fibroepithelial polyp, skin tag and soft fibroma; V. common, skin colored pedunculate papule on eyelids, axiallary area, neck or groin

-Histo: Fibrovascular core covered by epidermis, No adnexal structures incore;

epidermoid cyst-follicular infundibular cyst; V. common nodule,

-Histo: Dermal based cyst lined by epidermis filled by keratinous material; No relation to sebaceous gland

common epi lesion in older pt that are induced by sun expo and are hyperkeratosis; Precursors to SCC; on head, neck, hands and other sun exposed areas

-Keratinocytic dysplasia, hyperkeratosis, parakeratosis

In sun expo skin, or areas exp to irradiation, chronic ulcers, burn scars, HPV; Dx early so not many metastases;

-Histo: Prolif of atypical keratinocytes that invade dermis, look like nl squamous cells or poor differentaied where they loose squamous ft and become more atypical (lg pleomorphic nuclie & scant cytoplasm)

most common CA; malignant, grow slowly, rarely metastasize; occur in sun exp areas; look like pearly papules w/ prominent telangectasia, ulcerate

-Histo: aggregates of basaloid cells w/ palisaded arrangment of cells at periphery and celft at tumor-stroma interface, four growth patterns (superficial, nodular, micronodular, infiltrative)

Common benign; firm papule/nodule on legs

Histo: poorly circumscribed incr spindle shaped fibroblasts in dermis; epidermal hyperplasia and basal layer pigmentation

vascular tumor in young pt following trauma and during pregnancy; solitary and bleeding papule and pendunculated in fibbers or gingiva

-Histo: prolif of blood vessels in lobular arrangement; commonly ulcerated

mesenchymal cells; uncommon and occurs in: head/neck of older pt, area of previous radiation, setting of lymphadema; Ill defined dark plaque

Histo: atypical cells poss forming interanatomosing vascular channels or arranged as solid sheets of cells

itchy plaques that develop and fade w/in hrs; each episode lasts days to mnths; d/t mast cell degran in dermis leading to incr vascular permeability and edema

-IgE mediated type I hypersensitivity

clinical fidings are dramatic, but on histo find sparse interstitial infiltrates of eos and PMNs that is called Reticular dermal edema.

What is dx?

-red papular and vesicular lesion w/ scale crusty poss developing into thick scaly plaques

-spongiosis, which is edema in epidermis (fluid bt keratinocyts); over time less sponigiosis and more epidermal hyperplasia and hyperkeratosis, correlating w/ thick scaly plaque (lichen simplex chronicus) caused by rubbing/scratching

-Histo: epidermal hyperplasia, attenuated granula layer, thickened cornified lyaer w/ confluent parakeratosis and collection of PMNS;

-thick silvery white scale is thickened cornified layer

histo: superficial and deep infiltrate of lymphocytes in dermis, atrophy of epidermis, hyperkeratosis, pluggin of follicular infunbidulum, CT muscin depot w/in dermis

-IF: full house along DEJ w/ IgG, IgM, C3

Abs to desmosome which leads to loss of cohesion of keratinocytes (acantholysis)= blisters on skin and mucous membranes

-suprabasal vesicle formation at level of epidermis meaning that blisters form above the basal layer

IF- fishnet pattern w/ IgG btw and @ invidiv keratonocytes

Ab against bullous pemphigoid Ag 1 and 2 causing blisters at DEJ meaning blisters at subepidermal level; Dermal infiltrate of eos

IF- linear depo of IgG and C3 along DEJ; elderly, blisters tend to be tense and not fragile

IgA ab protein found in gluten, they cross react w/ Ag at papillary dermis resluting in pruritic papules, vesicle or bulla; Symmetric lesion on elbow, knee, butt;

-strong assoc w/ celiac dz and gluten

Histo: collection of PMN (neutrophilic microabcess) at tips of dermal papilla w/ focal cleavage at DEF

-IF: IgA at tips of dermal pailla

-caused by HPV; spread by direct contanct

-Histo: epidermal hyperplasia w/ papillomatosis hyperkeratosis and course keratohyaline granules w/in the granular layer; +/- koliocytes

-common in kids and teens; direct contact spread;

 small umbilicated skin colored papules; solitary or multiple

-molluscum contagiosum is cuased by what microorganims?

-What does the molluscum body contain?

-Pox virus

-Molluscum body: collectiono f viral particles w/in cells visible by LM

-The scale of this dz is correlated w/ parakeratosis w/ PMNs in cornified layer;

-PAS stain highlights hyphae in cornified layer

-contagious and pruritic; sparse but occasional #s papules, vesicles, and pustules in axilla, groin, genitals, fiber web;

-Histo: acute mitein subcornal zone, ID eggs of scybala in same location; Demris shows infiltrate of lymphocyte and eos