Skin Flashcards
Diagnostic test of both basal cell and squamous cell carcinoma, and melanoma
Full thickness incisional (or punch) biopsy done at the edge of the lesion (including normal skin)
Consider this type of skin cancer when you see a raised waxy lesion or a nonhealing ulcer. It has a preference for the upper part of the face (above a line drawn across the lips).
Basal cell carcinoma
How does basal cell carcinoma spread/kill
It does not metastasize but can kill by relentless local invasion (“rodent ulcer”).
Tx for basal cell carcinoma
Local excision with negative margins (1 mm is enough) is curative, but other lesions may develop later.
Which skin cancer shows up as a nonhealing ulcer, has a preference for the lower lip (and territories below a line drawn across the lips), and can metastasize to lymph nodes.
Squamous cell carcinoma
Tx for squamous cell carcinoma
Excision with wider margins is needed (0.5 to 2 cm), and node dissection is done if they are involved. Radiation treatment is another option.
ABCDE of melanoma
Asymmetry Borders (irregular) Color (different w/in lesion) Diameter (>0.5 cm) Evolution (change over time)
Suspect this in any pigmented lesion that changes in any way (grows, ulcerates, changes color and/or shape, bleeds, etc.)
Melanoma
Excision vs depth of melanoma
Lesions less than 1 mm deep have a good prognosis and only require local excision. Deeper lesions require excision with wide margins (2–3 cm). Lesions larger than 4 mm have a terrible prognosis. Lesions between 1 and 4 mm benefit most from aggressive therapy, including node dissection.
Where can metastatic malignant melanoma spread to?
All the usual places (lymph nodes, liver, lung, brain, and bone), but it also is the all-time champion for metastasizing to weird places (the muscle of the left ventricle, the wall of the duodenum. . . anywhere!). Furthermore, it has no predictable timetable. Some patients are full of metastases and dead within a few months of diagnosis; others go 20 years between the resection of their primary tumor and the sudden explosion of metastases.
Preferred adjuvant systemic tx for melanoma
Interferon
Most common cause of death from skin cancer
melanoma
Common pathway for increased risk of skin cancer
Excessive exposure to UV light, particularly UVB. Immunosuppression. For SCC and BCC, the risk is greatest with cumulative long-term UV exposure. With melanoma, blistering sunburns and overall sun exposure are risk factors. Skin cancer is also more common in patients who have fair-colored skin and hair and blue eyes.
Hair growth on skin nevi vs melanoma
Hair growth on a skin lesion suggests that it is a benign nevus. Melanomas destroy hair follicles.
Ugly duckling sign
Any skin lesion that looks different or out of place and thus an “ugly duckling,” in a nest of other similar appearing lesions is suspicious and recommended for biopsy.
On What Areas of the Skin Are Melanomas Most Likely to Occur in Non-white Ethnicities?
African American, Asian, and Hawaiian populations, melanomas most often occur on areas of nonexposed skin with less pigment such as the palms, soles, mucous membranes, and nail regions.
What Is the Most Common Site of Melanoma in Men Versus Women?
For men, the back is the most common site, while the legs are the most common site for women.
The most common site of digital melanoma
Great toe. Amputation and sentinel lymph node is the preferred treatment.
What Is a Nevi? Are Nevi a Risk for Malignant Transformation?
An additional risk factor for melanoma includes dysplastic nevus syndrome characterized by multiple dysplastic nevi with increased risk for progression towards melanoma (10 % risk).
What Is the Most Common Skin Cancer? Second Most Common? Which Skin Cancer Is Associated with the Greatest Number of Deaths?
Basal cell carcinoma is the most common skin cancer (and most common overall cancer), followed by squamous cell cancer,
whereas melanoma accounts for the most deaths.
What Is the Most Common Precancerous Skin Lesion?
Actinic keratosis. A rough scaly epidermal lesion, in an area of subjected to chronic sun exposure. About 10–20 % undergo malignant transformation to SCC. Some actinic keratosis can be pigmented.
Bowen’s Disease
It is a squamous cell carcinoma in situ. It appears as a well-defined erythematous plaque covered by an adherent scaly yellow crust. There is no potential for metastasis.
Most common metastasis to the small bowel
Melanoma
Metastatic potential of BCC, SCC, and melanoma
Basal cell carcinoma can be locally destructive; metastases are rare.
Squamous cell carcinomas do metastasize, but much less commonly than melanoma.
The most common site for melanoma to metastasize is to other areas of the skin, followed by, lung, liver, brain, and bone.
4 Subtypes of Melanoma
Superficial spreading (50-60%), Lentigo Maligna (4-10%), Acral lentigous (2-3%), Nodular (10-30%)
Most common type of melanoma, typically has a long horizontal growth phase before the vertical growth phase therefore better prognosis
Superficial spreading
Freckled proliferation of this melanoma indicates the tumor remains at the junction, best prognosis, AKA “Hutchinson freckle”
Lentigo maligna
Melanoma typically found in the subungual, sole, or palm location, common in ethnic groups of color.
Acral lentiginous
Melanoma with the worst prognosis due to rapid vertical growth, increased metastatic potential, 5% amelanotic
Nodular
After diagnosis of melanoma is confirmed, what should be the workup?
Chest x-ray, complete blood count, liver function tests, and serum lactate dehydrogenase (LDH) to rule out metastatic disease. If lymph nodes are palpable, get a CT of chest, abdomen, pelvis. If CNS symptoms, get MRI of brain.
Primary therapy for SCC and BCC
Excisional biopsy. Patients with lesions in cosmetically sensitive areas, aggressive tumor features, ill-defined lesions, or recurrent BCC/SCC are candidates for Mohs surgery (named after Dr. Frederic Mohs).
Surgical margins needed for BCC vs SCC
BCC: 3-5 mm
SCC: 5-10 mm
Which type of BCC has the worst prognosis
Morpheaform. Characterized by collagenase production.
Indications for lymph node dissection with melanoma
Reserved for patients with clinically palpable disease or those with a positive sentinel lymph node biopsy..
Prognosis for melanoma
When disease is confi ned to the primary site, 5-year survival is 80–90 %. If lymph nodes are involved, this decreases to 30–50%. Those with distant metastases have poor prognosis (10–15% 5-year survival).
Medical therapies for metastatic melanoma patients
Ipilimumab, a CTLA-4 blocking antibody, and vemurafenib, a small molecule inhibitor which blocks B-raf, have both been shown to improve overall survival
Surgery for cosmetically sensitive areas for the resection of melanoma
Moh’s procedure
Consider this in a diabetic patient presenting with a painful, erythematous, swollen leg with bullae and violaceous skin along with radiographic evidence of gas bubbles within the soft tissues of the leg.
Necrotizing soft tissue infection (NSTI)
Risk factors for necrotizing soft tissue infection
Factors that depress immunity and/or decrease tissue perfusion. Diabetes mellitus, malnutrition, intravenous (IV) drug abuse, obesity, chronic alcohol abuse, chronic lymphocytic leukemia, chronic steroid use, renal failure, peripheral arterial disease, and cirrhosis.
What Is the Implication of Crepitus? Bullae? Violaceous skin?
Crepitus: implies the presence of gas within the tissues, most likely due to the presence of gas-forming organisms.
Bullae: implies partial tissue death within the layers of the skin that allows for the collection of fluid between tissue layers.
Violaceous skin: violet or purple discoloration secondary to ischemia.
Hard signs of necrotizing soft tissue infection (NSTI).
Hypotension, crepitus, skin necrosis and bullae, and gas on X-ray are “hard signs” of NSTI.
Typical organisms seen in NSTI
Monomicrobial or polymicrobial.
Type I NSTI is a polymicrobial infection.
Type II NSTI is an infection with group A Streptococcus.
Type III NSTI is also known as clostridial myonecrosis and is caused by Clostridium perfringens.
Other term for necrotizing myositis
gas gangrene
What should you suspect if you culture Clostridium septicum from a wound?
Clostridium septicum infection can lead to gas gangrene and is associated with occult malignancies, most often colon cancer.
NSTI that involves the scrotum and/or perineum
Fournier’s gangrene
Management of NSTI
Initial tx: IV fluids, broad-spectrum IV antibiotics, and aggressive surgical debridement. This is the gold standard.
Intraoperative findings of NSTI
Murky fluid (i.e., dishwater fluid), gray discoloration of the fascia, and lack of bleeding from the fascia. Additionally, the fascia may separate from the muscle too easily, without the normal resistance on digital exploration.
Imaging that may be beneficial in the diagnosis of NSTI
Plain X-rays are useful if they demonstrate gas in the soft tissue. CT scan may also be beneficial. Looking for asymmetric fascial thickening (80%), gas tracking along fascial planes (55%), and abscess formation (35% ).
Lab values that help you point to NSTI instead of cellulitis
Low serum sodium and high WBC
