L6 - Derm Pathology Flashcards
What are the signs of dysplasia?
Disordered growth Loss in uniformity of the individual cells Loss of architectural orientation Pleomorphism Hyperchromatic Increased mitosis (normal and abnormal)
Which mutations occur in melanocytic nevi?
Activating mutations in components of the RAS or BRAF signaling pathway
What are junctional nevi?
Nests at dermoepidermal junction
What are compound nevi?
Nests or cords grow into underlying dermis
Nests in epidermis and dermis
Which genes are involved in dysplastic Nevus syndrome?
CDKN2A or CDK4 genes
Dsyplastic nevi often acquire activating mutations in which genes?
NRAS and BRAF genes
What are the ABCDEs of melanoma?
Asymmetry Irregular Borders Variegated Color Increasing Diameter Evolution/change over time (esp rapid) Any pigmentated legion with diameter >6mm, any change, itching or pain
What characteristics are associated with a favorable prognosis for melanoma?
Thinner tumor depth NO (<1 per mm) mitosis Brisk tumor infiltrating lymphocyte response NO regression Lack of ulceration
What is the Leser Trelat sign?
Paraneoplastic syndrome
Sudden appearance of large numbers of Seb Ks
Associated with carcinomas of GI tract
Describe nevoid BCC syndrome
AD inheritance
PTCH gene
Developmental patterning gene/ multiple BCC
Medulloblastoma, jaw cysts
Describe Cowden syndrome
AD inheritance
PTEN
Lipid phosphatase/benign follicular appendage tumors (tichilemmomas); internal adenocarcinoma (often breast or endometrial)
Describe familial melanoma syndrome
AD inheritance
CDKN2
Describe Muir-Torre syndrome
AD inheritance
MLH1/MSH2
Involved in DNA mismatch repair/sebaceous neoplasia
Internal malignancy (colon and others)
Describe xeroderma pigmentosum
AR inheritance
XPA gene
Mutation in NER
Increased risk for SCC, melanoma and non melanoma skin cancers
What is actinic chelitis?
Similar lesions to actinic keratosis on the lips
What is the second MC tumor arising in sun exposed sites?
Squamous cell carcinoma
What signaling pathway and gene is affected in BCC?
Unbridled hedgehog signaling
PTCH gene
What are pearly papules associated with?
BCC
Also have telangiectactic vessels
What translocation is associated with dermatofibrosarcoma protuberans (DFSP)?
Translocation collagen 1A1 (COL1A1) and PDGFB
Promoting tumor cell growth
The honeycomb pattern is a pathologic characteristic of which condition?
DFSP
It is a deep extension from the dermis into the SubQ fat
Also called Swiss cheese appearance on histo slides
Also associated with storiform (swirling spindle cells)
What is sezary syndrome?
Erythroderma, diffuse erythema and scaling of entire body surface ‘
What are sezary cells?
Markedly folded nuclear membrane, hyper convoluted or cerebriform contour
Band like aggregates within the superficial dermis
Pautrier microabscesses (small clusters of cells in the epidermis)
What is solitary mastocytoma?
Usually young kids
Pink-tan brown nodule
+/- pruritic or blister formation