dermatopathology part 2 Flashcards
seborrheic keratosis
most common benign tumor in older individuals
begin as light brown flat macules
later they develop a velvety or waxy to finely verrucous surface
color may vary from pale brown with pink tones to dark brown or black
typically have an appearance of being stuck on the skin surface and crumble with scraping
the sign of leser trelat is the association of multiple eruptive seborrheic keratoses with internal malignancy
biopsy if suspicious for melanoma
dermatosis papulos nigra
brown to black, smooth dome shaped papules
can be numerous
most often seen on african americans
sub type of seborrheic keratosis
no treatment necessary (can be treated with electrodessication)
treatment with liquid nitrogen can cause hypopigmentation
Seborrheic keratosis histology
exophytic
show sheets of small basaloid cells
frequently pigmented
exuberant keratin production at surface
small keratin filled cysts known as horn cysts
loose laemellar “shredded wheat” or “onion skin” keratin
acanthosis nigricans
hyperpigmentation is first
hyperplasia of stratum spinosum makes skin thick and velvety
usually found in folds of the neck, axilla, and groin
80% are benign type; usually occurs in childhood or puberty; may be associated with endocrine abnormalities (example: DM)
malignant type occurs in middle aged and older, associated with visceral malignancy
may be early indication underlying disorder
epidermal (inclusion) cyst
a top 10 benign lesion
inflamed vs “quiet”
common on the head and/or neck in children
histologic: cyst wall resmebles normal epidermis filled with strands of keratin
if inflammed may be surgically excised.
actinic keratosis
earliest identifiable lesion that can develop in squamous cell carcinoma (SCC)
up to 60% of SCCs develop from actinic keratoses
one prospective study estimated that one AK/1000/year transform into SCC, while other studies predict that from 5-20% of all untreated AKs will progress to SCC
Risk factors: years of sun exposure, fair skin, immunosuppression
studies have shown that a patients with 10 or more AKs has a 10-15% risk of developing SCC
actinic keratosis gross descption
palpation is key to early diagnosis
initially may be hard to see but will have areas of rough or gritty skin
discrete, scaly, feels like “broken glass” surface lesion
devleop into poorly demarcated, slightly erythematous papule or plaque with adherent scale
commonly found on sun exposed areas: face, scalp, ears, posterior neck, forearms and legs
actinic keratosis histology
parakeratosis (retained nuclei) in stratum corneum
hyperplasia and cytologic atypia of basal layer cells
solar elastosis in superficial dermis
actinic keratosis treatment and other factors
no definitive way to dsitinguish between an AK and SCC without biosy use lcinical judgement for management
treatment of choice for isolated lesions is cryotherapy (liquid nitrogen)
5 fluorouracil is effective topical tx. for supperficial AK’s with major side effect of intense inflammation
other treatment options: excision electrodissection and curettage, CO2 laser, and imiquimod, photodynamic therapy
actinic keratosis treatment side effects and other things
if you use crytotherapy, it is normal for the patient to get mild blistering and then a scab that leads to the lesion falling off
however, if the patient returns for a follow up in 2-3 months and the lesion is now ulcerated or thickened compared to before, a biopsy is warranted to r/o SCC; recurrence is normal but thickened and tender lesions have a greater risk for progression to cancer
5FU often used when multiple lesions appear on face, neck and scalp; daily BID 2-4 weeks
imiquimod immune response modifier BID-TID 4-16 weeks
Non melanoma skin cancer
most common cancer in the US about equal to all other cancers combined
80 are basal cell carcinomas (BCC) and 20% are squamous cell carcinomas (SCC)
after developing an initial BCC or SCC, patients have approximately a 50% chance of devleoping another NMSC
Squamous cell carcinoma presentation and risk factors
may present as a variety of primary morphologies with or without associated symptoms
arises in the epithelium and is common in the middle aged and elderly populations
risk factors: male, elderly, UV and ionizing radiation, fairskin, arsenic, HPV, sites with chronic infection, thermal burn scars, and immunosuppression but UVB and UVA most important
common on the scalp, dorsal upper extremities, and ears
SCC in situ
can present with scaly pink patch or a thin keratotic papule
bowen disease
subtype characterized by a sharply demarcated pink plaque and can arise on non sun exposed skin
erythroplasia of queyrat
bowen disease of the galns penis, which manifests as one or more velvety red plaques
