20 - 111 - BASAL CELL CARCINOMA AND BASAL NEVUS SYNDROME Flashcards
All statements regarding BCC are true, except:
a. Basal cell carcinoma (BCC) is the most common cancer in humans.
b. Men are affected slightly more often than are women.
c. BCC is rare in dark skin
d. BCC develops on sun-exposed skin in older adults, most commonly on the head and hands.
ANSWER:D p.1884. BCC develops on sun-exposed skin in older adults, most commonly on the head and neck.
a. Nodular BCC
b. Pigmented BCC
c. Superficial BCC
d. Morpheaform BCC
2. The melanocytes are interspersed between tumor cells and contain numerous melanin granules in their cytoplasm and dendrites.
3. most common clinical subtype of BCC
3. This histologic subtype is encountered most often on the trunk and extremities but may also appear on the head and neck.
4. consists of strands of tumor cells embedded within a dense fibrous stroma.
5. appears as an often well-demarcated erythematous patch
B, A, C, D, C, p. 1886-1887
classically presents as a pink papule, usually on the lower back
a. Basosquamous carcinoma
b. Superficial BCC
c. Sclerosing infiltrative BCC
d. Fibroepithelioma of pinkus
ANSWER: D. P. 1888 FEP classically presents as a pink papule, usually on the lower back. It may be difficult to distinguish from an acrochordon or skin tag.
it is the treatment of first choice for primary facial BCCs with an aggressive histopathological subtype and for recurrent facial BCCs
a. Moh’s micrographic surgery
b. Standard excision
c. Curettage and dessication
d. 5-Fluorouracil
ANSWER: A. Based on the fact that MMS provides the lowest recurrence. it is the treatment of first choice for primary facial BCCs with an aggressive histopathological sub- type and for recurrent facial BCCs
Approved by the FDA in 2012 for patients with locally advanced or metastatic BCC.
Vismodegib was approved by the FDA in 2012 for patients with locally advanced or metastatic BCC.
All are most characteristic abnormalities in BCNS, except:
a. Medulloblastomas or BCCs
b. Pits of the palms and soles,
c. PTCH gene mutation
d. odontogenic cysts of the jaw.
ANSWER: C. P.1891 In BCNS, the three most characteristic abnormalities are tumors such as medulloblastomas or BCCs, pits of the palms and soles, and odontogenic cysts of the jaw.
All are major criteria in BCNS except:
a. Medulloblastoma
b. Plantar pits
c. First-degree relative with BCNS
d. Splayed ribs
ANSWER:A. P.1895 table 111-4.
T/F. All BCCs have mutations activating the Hedgehog signaling pathway.
True
Risk factors for BCC
- ultraviolet radiation (UVR) exposure
- light hair and eye color
- northern European ancestry
- inability to tan
Common mutations that activate the aberrant Hedgehog signaling pathway
- loss of PTCH1 or Suppressor of Fused (SUFU) and activation of Smoothened (SMO)
commonly seen features of BCC
translucency, ulceration, telangiectasias, and the presence of a rolled border
Most common type of BCC
- Nodular
- Superficial
- Morpheaform
Nodular and morpheaform are most commonly found where?
head and necks
Superficial BCC is most often found where?
Trunk
Most Common Genes Mutated in Sporadic Basal Cell Carcinoma
Most common gene mutated in BCC
PTCH1
Enumerate the BCC subtypes
- Nodular BCC
- Pigmented BCC
- Superficial BCC
- Morpheaform/ Sclerosing/ Infiltrative BCC
- Basosquamous Carcinoma
- Fibroepithelioma of Pinkus
subtype of nodular BCC that exhibits increased melanization
Pigmented BCC
The lesions of this type of BCC may have an ivorywhite appearance and may resemble a scar
MORPHEAFORM (SCLEROSING, INFILTRATIVE BASAL CELL CARCINOMA)
Characterized histologically by strands of tumor cells embedded within a dense fibrous stroma
MORPHEAFORM (SCLEROSING, INFILTRATIVE BASAL CELL CARCINOMA)
Nodular BCC
Pigmented BCC
Superficial BCC
Morpheaform BCC
these treatments appear to be the most effective for BCC
Surgery and radiotherapy
gold standard for treating BCC
removal of the tumor with clear margins
What type of BCC will you consider nonsurgical treatment?
What is the FDA-approved therapy for metastatic BCC?
Vismodegib
What are the FDA-approved therapy for locally advanced BCC?
Vismodegib, Sonidegib
treatment of choice for morpheaform, poorly delineated, incompletely removed, high-risk primary BCCs and recurrent BCCs
MOHS MICROGRAPHIC SURGERY
treatment of first choice for primary facial BCCs with an aggressive histopathological subtype and for recurrent facial BCCs
MOHS MICROGRAPHIC SURGERY
Two freeze–thaw cycles with a tissue temperature of _________ are required to destroy BCC
−50°C (−58°F)
Approved in 2004 by the U.S. Food and Drug Administration (FDA) for the topical treatment of biopsy-confirmed, small (<2 cm), primary superficial BCC
Imiquimod
T/F. The more severe the local skin reaction (erythema, erosion, and crusting), the higher the clearance rate.
True
Imiquimod is FDA approved only for what type of BCC?
Superficial BCC
may be a very useful modality as adjunct treatment for BCC when margins are positive after excision or for extensive perineural or large nerve involvement
Radiation Therapy
this term is applied to BCCs that cannot be adequately excised without significant functional impairment or tumors that cannot be treated with radiotherapy.
Locally advanced BCCs
The most common sites of metastasis of BCC
regional lymph nodes, lungs, and bone
What are the risk factors for metastasis
Aggressive histologic characteristics, including morpheaform features, squamous metaplasia, and perineural invasion
The median survival period of patients with metastatic BCC
10 months
approved by the FDA in 2012 for patients with locally advanced or metastatic BCC.
Vismodegib
An estimated how many percent of patients with primary BCC will develop at least one or more further BCCs within 5 years?
40% to 50%
Recent clinical trials have highlighted a potential role of these 2 drugs in producing some decrease in BCC risk
- nicotinamide 500 mg BID
- celecoxib (NSAID)
Patients with basal cell nevus syndrome (BCNS, Gorlin syndrome) inherit an inactivating mutation in what gene?
PTCH1/ PATCHED1 gene (residing on the long arm of chromosome 9)
mode of inheritance of basal cell nevus syndrome (BCNS, Gorlin syndrome)
Autosomal Dominant
In BCNS, wha are the three most characteristic tumor abnormalities?
- Medulloblastoma or BCCs
- Pits of the palms and soles
- Odontogenic Cysts of the jaw
Major Criteria for BCCN
- Basal cell carcinoma before age 20 yr
- Odontogenic keratocysts before age 15 yr
- Three or more palmar or plantar pits
- Bilamellar calcification of the falx cerebri (if younger than 20 yr)
- Fused, bifid, or markedly splayed ribs
- First-degree relative with BCNS
- PTCH gene mutation in normal tissue
Minor Criteria for BCCN
- Macrocephaly determined after adjustment for height
- Congenital malformations: cleft lip or palate, frontal bossing, “coarse face,” moderate or severe hypertelorism
- Skeletal abnormalities: Sprengel deformity, marked pectus deformity, or marked syndactyly of the digits
- Radiologic abnormalities: bridging of the sella turcica; rib anomalies such as bifid or splayed ribs; vertebral anomalies such as hemivertebrae, fusion, or elongation of the vertebral bodies; modeling defects of the hands and feet; or flame-shaped lucencies of the hands or feet
- Ovarian fibroma
- Medulloblastoma
most effective agent in patients with BCNS
oral vismodegib 150 mg/day
pivotal abnormality in all BCCs
Malignant activation of the sonic hedgehog (SHH) signaling pathway
majority of BCCs were found to have mutations in HH pathway genes, most commonly what?
PTCH1 (73%)
SMO (20%), and SUFU (8%)
Sporadic BCCs also commonly harbor mutations in what gene?
TP53
often are the first detectable abnormality in BCNS
Jaw cysts
presumably form from inappropriate SHH induction of dental epithelium and can recur often and be the most debilitating aspect of BCNS
Jaw cysts
frequently the initial sign of BCNS.
childhood tumors (such as medulloblastoma)
What is the typical latency period between time of UV damage and clinical onset of BCC?
20 - 50 yrs
Why is BCC rare in individuals with dark skin?
because of the inherent photoprotection of melanin and melanosomal dispersion
T/F: In the US, BCC is 75% of all NMSC and 25% of all cancers overall.
True
What are the 4 risk factors for BCC formation?
UVR
light hair and eye color
northern European ancestry
inability to tan
Fill in the blanks: ___ type is/are commonly found in the head and neck, while ____ type is/are common in the trunk.
nodular & morpheaform
superficial
What type of treatment for BCC appear to have good cosmetic outcomes?
PDT
What is the standard treatment of choice for BCC?
surgical excision
T/F: Imiquimod is indicated for both superficial BCC and actinic keratosis, while 5-FU is approved for superficial BCC.
False
imiquimod - superficial BCC
5-FU - AK and superficial BCC
What are the risk factors for BCC metastasis?
morpheaform
squamous metaplasia
PNI
What is the FDA approved drug for metastatic BCC that may lead to tumor resistance?
sonidegib
T/F: BCNS is has incomplete penetrance and variable phenotypic expressivity.
complete penetrance
Fill in the blanks: ___ and ___ accelerated BCC formation in BCNS patients.
sunlight and radiation
Fill in the blanks: ___ is/are the first detectable abnormality, while ___ is/are frequently the initial sign of BCNS.
Jaw cysts
medulloblastoma
T/F: BCNS patients die earlier than sporadic BCC patients because of their disease.
False
No long-scale survival studies to determine whether BCNS patients die earlier because of their disease
Which drug is the most effective in preventing formation of new BCCs in BCNS patients?
vismodegib 150 mg/day
T/F: Surgical approaches to BCC treatment should be used aggressively to BCCs in BCNS.
False
Nonsurgical approaches
T/F: BCNS patients have multiple BCCs which are locally aggressive and have the potential to metastasize.
False
very rarely metastasize
Fill in the blanks: Suspect BCNS in a patient with BCCs before age of ___, odontogenic keratocysts before age of ___, and with ___ or more palmar or plantar pits.
What are the 3 most important aspects of management for BCNS?
frequent examination
counselling about sun avoidance
early treatment of small tumors
