Non-Melanoma Skin Cancer Flashcards
Actinic Keratosis Subtypes
Acantholytic AK, Bowenoid AK, Lichenoid AK, Atrophic AK, Hypertrophic AK, Pigmented AK, Actinic Cheilitis, Cutaneous Horn
AK Treatment Options
Cryotherapy, 5-FU, imiquimod, chemical peels, PDT
Bowen’s Disease variants
Atrophic, Verrucous, Pigmented, Pagetoid, Erythroplasia of Queyrat (on glans penis)
Erythroplasia of Queyrat
Bowen’s Disease of glans penis
Bowen’s Disease treatment options
Excision, C&E, PDT, Cryosurgery, imiquimod
SCC sites with high risk of metastasis
Lip or ear (10-20%), recurrent SCCs (up to 30%), arising within scars/chronic ulcers, perineural invasion, poor differentiation on histology, immunosuppression
Fold Increase Risk of SCC in organ transplant patients
65-fold
KA centrifugum marginatum
KA that may reach several centimeters in diameter, concomitant expansion of border and central healing
Giant KA
rapid enlargement of nodule to several centimeters
Ferguson-Smith type
sudden-onset of multiple KAs in childhood which will slowly resolve on their own; autosomal dominant
KA of Grzybowski type
sudden onset of multiple KAs in adulthood (eruptive pattern); very pruritis; mask like facial appearance due to thickened face skin; +Ectropion (drooping lower eyelids w/ retraction); hoarseness due to nodules on larynx
Fold Increase Risk of BCC in organ transplant patients
10-fold
Variants of BCC
Nodular, Superficial, Morpheaform, Basosquamous, Micronodular, Adenoid, Cystic, Fibroepithelioma of Pinkus
Fibroepithelioma of Pinkus
BCC variant appearing as pink plaque or smooth nodule on lower back
Most common BCC metastatic sites
Lymph nodes and lung
Treatment options for BCC
Excision, Mohs, C&E, RT, topical imiquimod (superficial BCCs)
Merkel Cell Carcinoma 5-year mortality
30%
Merkel Cell Metastasis rate at time of diagnosis
40%
Immunohistochemistry markers for Merkel Cell Carcinoma
CK20+, CK8/18/19 (CAM 5.2)+, chromogranin+, somatostatin+, calcitonin+, synaptophysin+, VIP+, neuron-specific enolase+
Merkel Cell Carcinoma treatment
Wide local excision (3cm margins) often with adjuvant chemo and/or radiation; sentinel node biopsy
Mutation in BCC (and role in pathway)
Patched- 12 transmembrane protein that binds to Smoothened (7 transmembrane G-protein) to prevent constitutive activation of Gli (also Bcl2 and TGF beta)
6 Hallmarks of Cancer
(1) self sufficiency in regards to growth signals
(2) insensitivity to anti-growth signals
(3) evasion of apoptosis
(4) limitless replicative potential
(5) sustained angiogenesis
(6) tissue invasion and metastasis
5-FU Mechanism
Blocks methylation reaction of deoxyuridylic acid to thymidylic acid, thus interfering with DNA/RNA synthesis
Ingenol mebutate mechanism
Hydrophobic diterpene ester (from plant Euphorbia peplus); induces mitochondrial swelling leading to cell death of keratinocytes by necrosis
Mechanism of Diclofenac in hyaluronic acid
NSAID that inhibits COX2 and reduces prostaglandin synthesis (thought to be increased in exposed skin)
Mechanism of PDT with ALA
Application of ALA leads to formation of protoporphyrin IX (PpIX), which can be irradiated with certain wavelengths, leading to reactive singlet oxygen formation
FAMMM Syndrome mutation
some cases…CDKN2A (p14ARF, p16); screen patients if 3 or more MM OR if 1 MM with family history (2 affected with MM or 1 pancreatic cancer)
3 wavelengths of UVR
UVC: 200-290nm; extremely mutagenic; mostly filtered out by atmosphere
UVB: 290-320nm; most important to carcinogenesis
UVA: 320-400; less potent mutagen but greater intensity than B so important
UVB mutagenesis
formation of cis-syn diastereomers of cyclobutane pyrimidine dimers and pyrimidine [6-4] pyridimidine adducts; both C–>T and CC–>TT at sequences with adjacent pyrmidine residuces (signature of UV-induced mutagenesis)
UVA mutagenesis
mediated through action of reactive oxygen species; T–> G transversions
Imiquimod mechanism
activates TLR7 and TLR8 leading to increased expression of NFKb
Bowenoid papulosis and associated infectious etiology
Verrucous papules/plaques (2-3mm) on penis or external femal genitalia; associated w HPV 16 or HPV 18
5 risk factors for leukoplakia transformation to SCC
Verrucous appearance, ulceration, presence of inlying nodule, induration, and presence on anterior floor of mouth or underside of tongue
Differential for Spindle Cell Skin Neoplasm
“SLAM”; SCC, leiomyoma, AFX, melanoma
Oral florid papillomatosis
HPV 11; verrucous carcinoma seen in mouth of elderly males and associated with tobacco use
Buschke-Lowenstein tumor
HPV 6, 11; giant condyloma acuminata
Epithelium cuniculatum
HPV 6, 11, 16, 18; verrucous carcinoma on plantar feet of elderly men
Muir-Torre Syndrome
KA, sebaceous neoplasms, and GI tumors; mutation of DNA mismatch repair genes MSH2, MSH6, MLH1, PMS2; autosomal dominant
Nevoid Basal Cell Carcinoma Syndrome
AD; Patched mutation; Multiple BCCs, palmar/plantar pits, skeletal abnormalities (increased head circ, frontal bossing, mild hypertelorism, rib abn, shortening of 4th metacarpal, jaw cysts- odontogenic keratocysts, calcification of flax cerebri); other neoplasms: medulloblastoma, ovarian fibromas, mesenteric cysts, meningiomas, fibrosarcomas, cardiac fibromas, ovarian desmoids
DDx for small round blue cell tumors
LEMMMONS: lymphoma, Ewings, Merkel cell, melanoma, metastasis, oat cell lung ca, neuroblastoma, small cell neuroendocrine tumor
Bazex Syndrome
B (BCCs), A (Atrophoderma), Z (zero hair), E (eccrine abn; anhidrosis), X (X-linked dominant)
Rombo Syndrome
similar to Bazex; KP-like lesions on face (atrophoderma vermiculatum), hypotrichosis, blepharitis, milia, peripheral vasodilation with cyanosis, multiple BCCs
Huriez syndrome
high risk cutaneous SCC and GI tumors; sclerodactyly, nail anomalies, and PPK
Xeroderma Pigmentosa
SCC=BCC>melanoma; AR; defect in DNA repair enzymes (XPA, XPC, and XPV); assoc with neuro abn and internal malignancies
Epidermadysplasia Verruciformis
AR; EVER1/EVER2; predisposes to widespread HPV infection; most common HPV 3, 5, 8; nail dystrophy +/- hyperkeratosis of plams/soles; can get early-onset SCCs
