BCC Flashcards
What proportion of basal cell carcinomas occur on the head and neck?
Four in five cutaneous basal cell carcinomas
Is upper lip cancer more common in men or
women?
It is more common in women: 21% of lip cancers on the
upper lip versus only 3% of lip cancer in men.
What percentage of cutaneous malignancies occur
on the lower lip?
90%
What is the significance of basal cell carcinoma
found in the folds of the face?
These tumors develop at the site of embryonic fusion
plates, resulting in more likely recurrence and higher risk of
spread. They therefore require close follow-up.
Is basal cell carcinoma more likely on the upper or lower lip?
Upper lip (13% vs. 1% of lower lip cancers)
What is the likelihood of regional nodal metastasis
in basal cell carcinoma?
Nodal spread is rare, occurring in fewer than 0.0028 to 0.5%
of patients.
What is the mechanism by which ultraviolet (UV)
B-wave light damages skin?
UV light in the B-band (280 to 320 nm), which is the same
wavelength responsible for sunburn, causes direct damage
to DNA by exciting DNA molecules, resulting in covalent
bonds between adjacent cytosine bases. These dimers are
read as “AA” by DNA polymerase, and therefore the
corresponding “TT” is added to the growing strand.
What are the risk factors for basal cell carcinoma?
Sun exposure is the most important risk factor, with other
factors including lightly pigmented skin, blue or green eyes,
and white ethnicity. Certain genetic conditions also
predispose individuals to basal cell carcinoma, including
basal cell nevus syndrome (also called Gorlin syndrome) and
xeroderma pigmentosum. Exposure risks include tanning
beds, arsenic, prior trauma, ionizing radiation, and immune
suppressants.
What are the so-called high-risk features used in
staging of basal cell carcinoma?
● Poor differentiation ● Perineural spread ● Origination in the ear or the hair-bearing lip ● Depth > 2 mm ● Clark level IV or V invasion
What percentage of nonmelanocytic cutaneous
neoplasms are basal cell carcinoma?
80%
What are the most commonly described types of
basal cell carcinoma?
There are 26 different subtypes of basal cell. The following
are the most commonly described:
● Nodular is the most common form of basal cell carcinoma
(60 to 80%), often described as pearly with rolled borders
and occasionally central ulceration.
● Morpheaform (or sclerosing or fibrosing) has irregular
borders on yellow plaques and is the most aggressive
type of basal cell carcinoma, with higher recurrence and
worse prognosis.
● Fibroepithelial
● Superficial is most common type on the trunk, irregularly
shaped, waxy, and with an occasionally eczematous or
psoriatic appearance.
● Other commonly described types are pigmented and
micronodular.
What percentage of basal cell carcinomas are
nodular?
56 to 78%
Which subtype of basal cell carcinoma has the
youngest average age at initial diagnosis?
Superficial, which is more common on the trunk
What aspect of morpheaform tumors render them
able to spread along embryogenic fusion planes
and therefore makes them more aggressive with
worse prognosis?
Morpheaform tumors secrete collagenases, enabling
movement between anatomic subsites.
Which subtype of basal cell carcinoma is much
more common in patients of African and Chinese
descent than those that are found in white
patients?
Pigmented basal cell carcinoma
Describe the clinical constellation known as nevoid
basal cell carcinoma syndrome (or Gorlin syndrome)
Patients are diagnosed at an early age with multifocal basal
cell carcinomas, odontogenic keratocysts, and often also
bifid ribs, scoliosis, developmental delay, and frontal
bossing.
Describe the characteristic features of nodular
basal cell carcinoma.
Classically, nodular basal cell carcinoma is described as a
pearly lesion with rolled borders, central ulceration, and
peripheral telangiectasias.
Describe the features associated with arsenic
exposure.
● Truncal basal cell carcinoma
● Keratoses of the palms and soles
● Nail changes (Mees lines)
What type of biopsy should be performed for a
suspected basal cell carcinoma?
Shave biopsy is appropriate for the vast majority of basal
cell carcinomas. When lesions are pigmented, a punch
biopsy should be performed to assess the depth of the
lesion.
When is imaging required in basal cell carcinoma?
Rarely: Large tumors, suspicion of invasion of deeper
structures (e.g., fixation, bone invasion), symptoms of
perineural invasion, palpable lymphadenopathy
What parts of the head and neck are at highest
risk of recurrence when affected by cutaneous
malignancies?
The preauricular and postauricular regions, floor of nose/
columella, medial and lateral canthi, nasolabial fold, aka the
so-called H-zone
Under what circumstances should cryosurgery
be considered for management of basal cell
carcinoma?
Cryosurgery can be used in small (< 1 cm) nonaggressive
tumors.
In the management of basal cell carcinoma, what tumor attributes favor excisional curettage and
electrodessication?
Small (< 2 cm), nonaggressive tumors can be removed with
excisional curettage with 90% success. Excisional curettage
is not optimal for management of functionally and
cosmetically important tumors.
What rate of cure can be expected with Mohs
surgery in basal cell carcinoma?
96 to 99% cure rate in recurrent and primary resections,
respectively
What are the advantages of Mohs surgery over
simple excision with electrodessication?
Maximal preservation of normal tissue, optimization of
functional/cosmetic outcomes, assessment, and clearing of entire margin, lower recurrence rates, immediate recon-
struction (usually), only one practitioner involved at all phases of management
What are the nonsurgical options for management
of basal cell carcinoma?
● Radiation therapy (most commonly used nonsurgical
therapy, although waning in popularity)
● Photodynamic therapy
● Immunotherapy
● Chemotherapy
● Vismodegib, an agent that targets the hedgehog signal-
ing pathway and was approved in 2012 for treatment of basal cell carcinoma
In patients with cutaneous basal cell carcinoma,
when should neck dissection be considered?
Neck dissection should be used only in instances when
there is clinical evidence of nodal metastasis because basal
cell carcinoma metastasizes to the lymph nodes in only
0.5% of cases.
Why is it best to defer reconstruction in the morpheaform type of basal cell carcinoma?
Morpheaform basal cell carcinoma classically exhibits
subdermal spread that results in more common recurrence
than other variants of basal cell carcinoma. Reconstruction
either with grafting or tissue rearrangement may cover this
subdermal extension and delay diagnosis of recurrence,
sometimes with devastating consequences for the patient.
