Week 7 - Basal cell carcinoma and actinic keratosis Flashcards
(41 cards)
Where does Basal Cell Carcinoma (BCC) develop?
Develop in the basal layer
What is the most common skin cancer?
Basal Cell Carcinoma (rare to have metastasis)
What are the problem areas of BCC?
BCC arising around the eyes, in the nasolabial folds, around the ear canal, and in the posterior auricular sulcus.
What are the chances of developing a BCC after already having one?
About 40% of patients who have had one BCC will develop another lesion within five year
Environmental Risk Factors of BCC?
Chronic UV radiation exposure most important risk factor!
Frequency and intensity of sun exposure - intermittent, intense increments increases the risk of BCC more than a similar dose delivered more continuously over the same period of time.
Childhood sun exposure with childhood freckling.
Increased number of past sunburns.
Persons with fair skin, light-colored eyes, red hair
Increased frequency in males, e.g. farmers with sun exposure
The use of tanning beds, particularly among young women
Exposure to chemicals e.g. arsenic
What is Nodular BCC?
Five clinicopathologic types of BCC
- Nodular BCC:
- Cystic, pigmented, keratotic
- MOST COMMON type of BCC
- Usually is a round or ovate, or flat, pearly, flesh-colored papule with telangiectasis
- Irregular growth pattern –> mass with multilobular surface
Some nodular BCCs are called “rodent ulcers”:
- Center ulcerates/bleeds, accumulates crust/scale
- Ulcerated areas heal with scarring
- Patients often assume their conditions are improving
- Cycle of growth, ulceration, and healing continues as the mass extends peripherally and deeper
- Lesions may become enormous!
What is Micronodular BCC?
Five clinicopathologic types of BCC
- Micronodular:
- Not prone to ulceration
- May appear yellow-white when stretched
- Firm to the touch
- May have a seemingly well-defined border
What is Infiltrative BCC?
Five clinicopathologic types of BCC
- Infiltrative:
Infiltrates the dermis in thin strands between collagen fibers – makes tumor margins less clinically apparent
May contain melanin –> brown, black, or blue color.
Clinically resemble a melanoma or pigmented seborrheic keratosis
Close inspection reveals characteristically elevated, pearly white, translucent border.
What is Morpheaform BCC?
Five clinicopathologic types of BCC
- Morpheaform (Sclerosing):
- Insidious tumor with innocuous surface characteristics that can mask its potential for deep, wide extension.
- Appears as a white or yellow, waxy, sclerotic plaque that rarely ulcerates.
- Flat or slightly depressed, fibrotic, and firm.
- Resembles localized scleroderma, thus “morpheaform”
- Borders are indistinct and blend with normal skin making border localization of this tumor by inspection impossible.
- Subclinical extension beyond clinically delineated borders averaged 7.2 mm in one study.
- Treatment - wide excision or, preferably, Mohs micrographic surgery
What is Superficial BCC?
Five clinicopathologic types of BCC
- Superficial:
- LEAST AGGRESSIVE BCC
- Mostly on the upper trunk or shoulders; also extremities and the face.
- Spreads peripherally, some times for several centimeters
- Invades only after considerable time.
- Appears clinically as a red, round-to-oval, well-circumscribed patch or scaling plaque, often with a whitish scale
- Resembles a plaque of eczema, psoriasis, extra mammary Paget’s disease, or Bowen’s disease.
- Careful inspection reveals thin, raised, pearly white nature.
How do you diagnose BCC?
Diagnosis must be confirmed by biopsy.
Leg ulcers that do not respond to treatment should be biopsied!
The biopsy sample may be obtained:
- at the same time as definitive local therapy (surgical excision)
- or by cryotherapy or curettage and electrodessication by a specialist!
DDX for Nodular BCC?
Early nodular variants with little ulceration:
- Clinically may be identical to benign growths such as dermal nevi, small epidermal inclusion cysts, or even sebaceous hyperplasia.
- A single lesion of molluscum contagiosum or amelanotic melanoma has a similar appearance.
Larger cup-shaped lesions with central ulceration:
- Can resemble squamous cell carcinoma, keratoacanthomas, or dermal metastases from internal organs such as the colon.
DDX for Superficial BCC?
Superficial BCCs (can look like a fungus):
- May not always be rimmed by pearly micropapules.
- Can be mistaken for contact or nummular dermatitis.
- May resemble psoriatic plaques without a characteristic scaly surface.
- Most difficult differentials are lichenoid keratoses, and inflamed seborrheic and actinic keratoses.
DDX for Morpheaform BCC?
Morpheaform BCCs (looks like a scar):
- Frequently appear similar to a scar or other site of trauma.
- When there is induration, BCCs may resemble melanoma or less likely a benign nevus.
How do you treat BCC?
BCCs must be treated early on to avoid the locally invasive, aggressive, and destructive effects on skin and surrounding tissues.
- Electrodesiccation & Curettage
- Surgical excision
- Mohs
- Cryotherapy
- Topical 5-Fluorouracil and Imiquimod
- Radiation Therapy
What are the ADVANTAGES of ELECTRODESICATION & CURETTAGE for BCC?
Five year recurrence rate:
Primary (small, low risk) BCCs – 8%
Recurrent BCCs – 18-40%
Advantages:
- Cost effective
- Relatively quick, single visit
- Relatively easy wound care
- Well suited for multiple lesions
- Usually affords good to excellent cosmetic results
- No sedation or general anesthesia required
What are the DISADVANTAGES of ELECTRODESICATION & CURETTAGE for BCC?
- Not margin-controlled.
- Recurrence rate unacceptably high with larger (>5 mm) lesions located in high risk sites!
- Need special equipment and user experience to get higher cure rates.
- Poor choice in most BCCs of the head.
- Must be cautious in patients with pacemakers.
What are the ADVANTAGES of SURGICAL EXCISION for BCC?
Five year recurrence rate:
Primary BCC – 5-10%
Recurrent BCC – 12-17%
Advantages:
- Margin-controlled.
- Usually performed under local anesthesia.
- Area of tissue removed can be more precisely controlled than with cryosurgery, radiation therapy, or electrosurgery limiting damage to critical structures.
- Resultant scar is optimized both cosmetically and functionally.
What are the DISADVANTAGES of SURGICAL EXCISION for BCC?
Disadvantages of Surgical Excision:
- Invasive
- Occasionally needs to be performed under conscious sedation or general anesthesia with their inherent risks.
- Uncertain “clear” margin a poorer cure rate compared to Mohs micrographic surgery
What is MOHS micrographic surgery?
Description of technique: During the surgery, after each removal of tissue, while the patient waits, the pathologist (often the surgeon) examines the tissue specimen for cancer cells under the microscope, and that informs the surgeon if and where to remove more tissue.
Five year recurrence rate:
Primary BCC – 1- 2%
Recurrent BCC – 5%
What are the ADVANTAGES of MOHS for BCC?
Advantages of Mohs:
- Cost effective: single visit – relatively quick (depends on lesion!)
- No sedation or general anesthesia required.
- Best procedure for producing high cure rates in lesions that exhibit features associated with an elevated risk for recurrence
- Best for situations in which tissue sparing is of great cosmetic or functional value.
- Allows for histological evaluation of 100% of the peripheral margin at the time of the surgical procedure.
What are the DISADVANTAGES of MOHS for BCC?
Disadvantages of Mohs:
- More costly than simple excision, cryosurgery or electrosurgery
- Invasive
- Longer procedure compared to simple excision, cryosurgery or electrosurgery
- Requires special training in the technique.
What are the ADVANTAGES of CRYOTHERAPY for BCC?
CRYOTHERAPY:
Five year recurrence rate:
Primary BCC – 8%
Recurrent BCC – 13%
Advantages of Cryotherapy:
- Cost effective
- Relatively quick – no sedation or general anesthesia required
- Relatively easy wound care
- Well suited for multiple lesions
- Usually affords good to excellent cosmetic results
- Low recurrence rates in small primary BCCs that lack “high risk” features
What are the DISADVANTAGES of CRYOTHERAPY for BCC?
Disadvantages of Cryotherapy:
- Not margin-controlled.
- May require multiple visits
- Requires considerable clinical judgment/experience
- Potential hyper- and hypo-pigmentation
- Possible permanent damage to underlying nerves, vessels, etc.
