Dermatopathology II-Fung Flashcards
Which components of the skin can neoplasms arise from?
epidermis: squamous or melanocytic
dermis
adnexal structures in the dermis: eccrine, apocrine, hair follicles
What is seborrheic keratosis?
benign neoplasm of unknown origin no malignant potential round flat lesions that is waxy. uniform or darkly pigmented velvety granular surface **may still want a biopsy just to be sure
What types of features might you see on histo of sebhorreic keratosis?
dome-shaped lesion
papillomatosis
hyperkeratosis
horn cysts
What are horn cysts?
invagination of epidermis into the dermis
then keratin production!
What is another name for a skin tag? What are they?
aka fibroepithelial polyps
no malignant potential
**stalk that connects to skin can become painful
What are the features of skin tags on histo?
loose stroma surrounded by epidermis
What are keloids? What is another name for them?
hypertrophic scars
abnormal dense deposition of collagen in the dermis
can come from ear piercings or acne
**African Americans have a higher propensity for these
What is an epidermal inclusion cyst?
invagination of epidermis into dermis & then production of keratin! sometimes can rupture & cause inflammatory response as keratin spills out.
What is actinic keratosis?
lesion that is due to sun damage
see tan brown or red colored lesion
skin feels like sandpaper
it is a dysplasia, but not a full carcinoma
What does actinic keratosis look like on histo?
see some hyperkeratosis
dermis has solar elastois (UV breaks down collagen that is normally in the dermis)
dyskeratosis
see some abnormal nuclei-dark & big for keratinocytes
What is squamous cell carcinoma in situ?
a more progressed form of actinic keratosis
but not invasive, contained w/i basement membrane
What is Bowen’s disease?
this is squamous cell carcinoma in situ in the genital region
What is basal cell carcinoma?
malignant epidermal tumor pearly papules some are pigmented locally aggressive tumor can erode into the bone if not taken care of! **can sometimes be mistaken for melanoma
What is the progression of melanocytic neoplasms: from benign–>malignant?
nevus
dysplastic nevus
melanoma
**most involved in Ras or Raf pathway
What is a nevus?
common benign neoplasm that is acquired by activating mutations in the Ras signaling pathway
experiences morphological changes over time
Describe the progression of a nevus.
junctional nevus: epidermis
compound nevus: epidermis & dermis
intradermal nevus: just dermis
What is a dysplastic nevus?
a possible direct precursor to melanoma
most are stable & don’t progress
have the check point of p16
have acquired a mutation in the NRAS & BRAF genes already, tho
What is melanoma?
deadly skin cancer
needs to be caught in early stages
can occur on skin or in oral, GI, or genital mucosa
What prompt melanoma?
some of it is aut dom inherited usu sporadic-UV radiation damage to DNA **affects cell cycle control genes activates pro-growth signaling pathways activates telomerase
What are the signs to look for that will tip you off to malignant melanoma?
A: asymmetry B: borders C: color D: diameter E: evolution ex: nevus matures & can form melanoma
What are 2 important growth phases of melanoma?
lentigomalignant melanoma
superficial spreading melanoma
What are the 2 types of growth of melanoma?
radial: grows w/i the epidermis **great if you can catch it here
vertical: worry about metastasis, goes thru the basement membrane & it is in the dermis
What is Breslow Thickness & what is its significance?
depth of invasion of a melanoma into a dermis
lower the number-the better!
What is Clarke’s level?
anatomical invasion level
Level 1-5
