Title: GZ / The Grenz Zone Season 2 / 16 Basal Cell Carcinoma
Tags: GZ DermnetNZ

The 4 main clinical subtypes of basal cell carcinoma are:
Nodular
Superficial
Morpheaform
Fibroepithelial (Fibroepithelioma of Pinkus)
Back Extra: Nodular
Superficial
Morpheaform

Q: The pathogenesis of basal cell carcinoma is thru the [...] pathway
A: sonic hedgehog

Q: [...] receptor is mutated in Basal Cell Nevus Syndrome (Gorlin Syndrome)
A: PTCH1

Q: Gorlin Syndrome requires [1 or 2] major OR 1 major and [1 or 2] minor criteria
A: 2; 2

Q: 3 important histological descriptors of a nodular basal cell carcinoma are:
[...]
[...]
[...]
A: peripheral palisading; retraction artifact; fibromyxoid stroma
Back Extra: peripheral palisading: outer most cells in tumor island line up along the periphery
retraction artifact: clear space between tumor island and surrounding stroma
fibromyxoid stroma: blue-grey mucinous background

Q: Some histological variants of basal cell carcinoma include:
[...]
[...]
[...]
A: micronodular; infundibulocystic; basosquamous
Back Extra: infundibulocystic: pearly pink papule on the head and neck. On histology, anastamosing pink strands and blue basal buds with horn cysts intermixed is seen
basosquamous: has features of both basal and squamous cell carcinoma on histology

Q: Common treatment options for basal cell carcinoma include [common surgical treatment], [...], or [...]
A: Mohs; radiation; wide local excision
Back Extra: Wide local excision should have 4mm margins
Other treatment options include ED&C, topical imiquimod or 5-FU, and cryosurgery

Q: On histology, superficial basal cell carcinoma presents with blue buds of basal cell stemming from the [...], which DO NOT go any deeper than the [...]
A: epidermis; papillary dermis

Q: Which main clinical subtypes of basal cell carcinoma are the most aggressive?
[...]
A: morpheaform & fibroepithelial

Q: On histology, morpheaform basal cell carcinoma presents as strands of basal cells cutting into the [...] in a jagged pattern
A: dermis
Back Extra: There is NO peripheral palisading and retraction artifact
There could be up to 7mm of subclinical spread, which makes is aggressive

Q: On histology, fibroepithelial basal cell carcinoma presents as thin strands of blue cells interconnecting to form a [...] structure
A: web-like
Back Extra: also considered an agressive form of basal cell carcinoma along with morpheaform

Q: Topical imiquimod is used in the treatment of superficial basal cell carcinoma and works by activating [specific receptor] which activates the immune system to target and destroy the BCC
A: toll-like receptor 7
Back Extra: more commonly used than 5-FU due to higher cure rate

Q: 2 commonly mutated genes in basal cell carcinoma are PTCH1 and [...]
A: p53
Back Extra: both of these genes are tumor suppressors

The 4 major components contributing to the pathogenesis of basal cell carcinoma are:
sonic hedgehog ligand
PTCH1 receptor
SMO (Smoothened)
Gli

Q: [...] and/or [...] block [...] and prevent downstream activation of Gli transcription factors
A: Vismodegib (Erivedge); Sonidegib (Odomzo); smoothened
Back Extra: they are used in the treatment of advanced or metatstatic BCCs. Also used in the treatment of Basal Cell Nevus Syndrome (Gorlin Syndrome)