SCC & BCC Flashcards
What is the standard of care for diagnosing nonmelanoma skin cancers?
Biopsy
Biopsy should include deep reticular dermis for evaluation of invasive disease.
What percentage of aggressive subtypes of SCC/BCC can punch and shave biopsies miss?
11-19%
This highlights the importance of thorough biopsy techniques.
What defines a high-risk lesion (SCC/BCC)?
A high-risk lesion includes:
* Poorly differentiated borders
* Recurrent lesion
* Immunosuppressed patient
* Site of prior radiotherapy
* Perineural involvement
* Aggressive histological subtype
* Lesion ≥ 20 mm on trunk/extremities
* Lesion ≥ 10 mm on scalp, forehead, cheeks, neck, pretibia
* Lesion in mask area of face, genitalia, hands, or feet
List aggressive histological subtypes for BCC.
- Morpheaform
- Basosquamous
- Sclerosing
- Mixed infiltrative
- Micro nodular
These subtypes are more likely to recur than nodular BCC and other variants.
What are the aggressive histological subtypes of SCC?
- Adenoid/acantholytic
- Adenosquamous
- Desmoplastic
- Metaplastic
These subtypes have unique characteristics that necessitate careful management.
What size and location criteria define high-risk SCC/BCC?
High-risk tumors include:
* Tumors ≥ 20 mm on trunk or extremities (except pretoria, hands/feet)
* Tumors ≥ 10 mm on scalp, forehead, cheeks, neck, or pretibia
* Any lesion in mask area/H zone
Measurements include the peripheral rim of erythema.
What unique high-risk features are associated with SCC?
- Chronic inflammation (Marjolin ulcer)
- Rapidly growing
- Neurologic symptoms
- Poor differentiation
- Depth of ≥ 2 mm
- Clark level IV or V
- Lymphovascular invasion
What is the treatment (margins) for low-risk vs. high-risk BCC and SCC lesions?
Surgical excision with post-op margins:
* 4 mm for SCC < 2 cm, well-differentiated
* 6 mm for SCC > 2 cm, invasive to fat, high risk location
- 4 mm for BCC
- 7 mm for BCC high risk
Mohs is not required for primary, low-risk lesions.
What is the 5-year disease-free survival rate for low-risk BCC? SCC?
BCC: 95-98%
The rate for low-risk SCC is 92%.
What is electrodissection and curettage used for in BCC/SCC rx?
It is used to denature and remove visible tumors.
Current age can help assist in defining the sub clinical margin, but surgical margin should be taken beyond that.
It does not allow for histologic margin assessment and has a 5-year recurrence rate of 3-9%.
When is radiation therapy reserved for SCC/BCC?
For nonsurgical candidates > 60 years old
It can also be used as adjuvant therapy for tumors with positive margins and perineural involvement; also if size > 2 cm, invasive to deep tissues, aggressive histological subtype (poorly differentiated)
What is the treatment for SCC in situ (Bowen disease)?
Options include:
* 5-FU or imiquimod
* Photodynamic therapy
* Cryotherapy
* Surgery (treatment of choice)
5-FU and imiquimod lead to 5-year recurrence rates of 10-16%.
What is the gold standard treatment for high-risk lesions (SCC/BCC)?
Mohs micrographic surgery
It has a 5-year survival rate of 99% for BCC and 97% for SCC.
What is the common treatment for actinic keratosis (AK)?
Cryotherapy is the most common treatment with cure rates as high as 98.8% - better for isolated lesions (< 15 lesions)
Diffuse lesions require topical field-directed therapy if widespread in an area with chronic sun damage (5-FU, imiquimod, diclofenac sodium, and internal mebutate used)
How is positive margin management determined for SCC/BCC? How do you address positive margins?
It depends on whether the lesion was high or low risk.
Low-risk lesions may require reexcision with Mohs, or if on trunk or extremities»_space; re-excision.
High-risk lesions: if WLE already done»_space; Mohs; if Mohs already»_space; tumor board for adjuvant therapy options; if not a candidate»_space; radiation
What is the risk of recurrence and mortality for lymph node disease in SCC?
> 7x increase
Management includes FNA or core biopsy and CT for staging.
What is a major disadvantage of Mohs surgery? Advantage?
Disadvantage: It requires two separate procedures when reconstruction is indicated.
Advantage: 100% margin assessment, superior cure rates, low morbidity, tissue conservation
List the Indications for Moh’s
- Morpheaform BCC
- Recurrent basal cell/squamous cell carcinomas;
- Locations prone to recurrence—“H-zone” of the face: periorbital, periauricular, temple, upper lip, nose/nasolabial fold, and chin;
- Tumors involving critical structures such as the eyelid or lip;
- Functionally important areas such as the genitals, perianal location, hands, and feet;
- Tumors arising in sites of previous irradiation therapy;
- Large tumors (greater than 2 cm);
- Lesions with ill-defined tumor margins;
- Histologic aggressive subtype (morpheaform, basosquamous, perineural/ perivascular, and invasive/poorly-differentiated squamous cell carcinoma);
- Tumors arising in immunosuppressed patients, such as transplant recipients or patients with genetic predisposition (e.g. basal cell nevus syndrome, xeroderma pigmentosum).
- ## Lesions in patients with basal cell nevus syndrome
What factors should be considered in the patient’s history when there is concern for malignant lesion?
- Length of time the lesion has been present
- Associated symptoms: Pain, itching, bleeding, hyperkeratosis
- Sun exposure history and tanning bed use
- History of facial surgery
- Previous treatment history
- Complicating comorbidities
- Personal or family history of skin cancer
- History of radiation, immunosuppression
- Genetic conditions
Genetic conditions include Xeroderma pigmentosum, Gorlin’s syndrome, albinism.
What are the key components of a physical examination for the lesion?
- Detailed evaluation of affected area and surrounding face/neck + characteristics of affected area (hair-bearing, adjacent skin laxity, pigmentation)
- Skin lesion findings (size, color, shape, irregularity, hyperkeratosis, ulceration). Confirm absence of involvement of deeper structures (parotid, facial nerve)
- Lymph node examination
- Full body integument examination
What is the recommended diagnostic study if a patient presents without previous treatment?
A biopsy should be performed.
Full-thickness incisional versus excisional biopsies may be performed.
What types of biopsies are considered for atypical pigmented lesions?
- Excisional biopsy
- Shave biopsy (acceptable for nonmelanoma skin cancer)
Avoid shave biopsies of a portion of a pigmented lesion to minimize sampling error.
What imaging study may be necessary after initial diagnosis, especially for scalp lesions?
Magnetic resonance imaging (MRI) may be necessary to determine extent of tumor and lymph node status.
Especially useful in cases of aggressive tumor histology.
What should patients be counseled about regarding their diagnosis?
- Diagnosis
- Prognosis
- Reconstructive options
Patients should understand that the size of the final defect cannot be anticipated until resection.
What are nonsurgical treatment options for low-risk basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)?
- Topical 5-fluorouracil
- Imiquimod
- Cryosurgery
- Electrodesiccation and curettage
- Radiation therapy
These options are associated with higher recurrence rates than surgical excision. Primarily for patients in which excision is contraindicated or impractical
What is recommended for high-risk BCC and SCC according to the American Academy of Dermatology?
Mohs micrographic surgery is recommended.
It allows examination of ~100% of surgical margins and has the highest cure rates.
What are the further high-risk criteria indicating the need for adjuvant radiation therapy?
- Size > 2 cm
- Perineural invasion
- Invasion into deep tissues (fat, muscle, bone)
- Aggressive histologic subtype (poorly differentiated)
These criteria help determine the aggressiveness of the melanoma and treatment options.
What is the most reliable method of confirming negative margins after excision?
Permanent sections
Fresh frozen pathologic evaluation is unreliable and cannot ensure negative margins.
What is the typical time frame for final results from permanent sections?
Over a week
This delay can impact subsequent treatment decisions.
When should reconstruction be delayed after excision of a malignant lesion?
Until negative margins are confirmed on final pathology
This ensures that all cancerous tissues have been removed.
What are some surgical pearls for reconstruction after malignant lesion excision?
- Mark or tattoo landmarks prior to injecting local anesthetic
- Replace ‘like with like’ (reconstruct all appropriate layers: skin, mucosa, cartilage/bone)
These practices improve surgical outcomes.
What is necessary if recurrent cancer or positive margins are found?
Re-excision is necessary
Reconstruction should only occur after achieving negative margins.
What treatments are indicated for wound dehiscence or partial flap necrosis?
Local wound care or readvance flap if adequate laxity is present
Proper management is key to recovery.
What is the treatment for infection following surgery?
Antibiotics and conservative debridement, if appropriate
Timely intervention can prevent complications.
How do you treat a Marjorlin Ulcer?
If suspected»_space; biopsy.
Rx with WLE of chronic wound + SLNB and rapid coverage. May require adjuvant radiation
Describe the presentation of SCC.
Presents as discrete, slow-growing lesion with history of bleeding or ulceration
Arises from keratinocytes in stratum basale
Describe the presentation of BCC.
Discrete, slow growing lesion with history of ulceration. Characteristic appearance = round oval nodules with shiny pearly appearance and overlying telangiectasias.
MC skin cancer, MCC = sun exposure
