Lecture 26 - Biology of Human Aging

Q: What is the treatment of choice for melanoma?

A: Surgical excision.

Q: What types of skin cancer can surgical excision treat?

A: All types of skin cancer.

Q: Why is surgical excision considered an effective treatment?

A: It produces excellent results both medically and cosmetically.

Q: What is the first step in surgical excision of a skin tumor?

A: The physician outlines the tumor with a marking pen.

Q: Why is a "safety margin" of tissue removed during surgical excision?

A: Because it is not possible to determine exactly how far the tumor has extended.

Q: What happens after the tumor and surrounding margin are removed in surgical excision?

A: The extended incision allows the skin to be sewn back together.

Q: What is Mohs surgery?

A: A surgical procedure where thin layers of skin cancer tissue are removed and examined under a microscope until no cancer cells remain.

Q: What is the main advantage of Mohs surgery?

A: It removes as little normal tissue as possible.

Q: Where is Mohs surgery commonly used?

A: On the face.

Q: What is the first step in Mohs surgery?

A: Removal of the visible tumor and a small segment of surrounding skin.

Q: What happens to the removed tissue during Mohs surgery?

A: It is examined under a microscope to check for remaining cancer cells.

Q: What happens if cancer cells are still present during Mohs surgery?

A: Additional layers of skin are removed and examined.

Q: What happens if cancer cells are still present during Mohs surgery?

A: When no more cancer cells are found under the microscope.

Q: What cells does malignant melanoma develop from?

A: Melanocytes.

Q: Where does malignant melanoma commonly develop on the skin?

A: In melanocytes of pre-existing moles.

Q: What age group is malignant melanoma most common in?

A: People aged 50–70.

Q: How many melanoma cases were diagnosed in the United States last year (approx.)?

A: About 60,000 cases.

Q: How many Canadians were diagnosed with melanoma in 2020?

A: About 8,000.

Q: How many Canadians died from melanoma in 2020?

A: About 1,300.

Q: How does malignant melanoma compare to other cancers in growth rate?

A: It is the fastest growing cancer.

Q: How frequently does malignant melanoma cause a death?

A: Approximately one life every hour.

Q: What is the most dangerous form of skin cancer?

A: Malignant melanoma.

Q: Why must moles be monitored regularly?

A: Because changes in size or texture may indicate malignant melanoma.

Q: Why is malignant melanoma particularly dangerous?

A: It can metastasize (spread to other parts of the body).

Q: What changes in a mole may indicate malignant melanoma?

A: Changes in color, enlargement, bleeding, or fuzzy/irregular borders.

Q: What colors can malignant melanoma appear as?

A: Brown, black, blue, or red.

Q: What environmental factor is strongly associated with the increase in malignant melanoma worldwide?

A: Repeated exposure to sunlight (UV radiation).

Q: Where is malignant melanoma most commonly found on men and women?

A: Upper back in both men and women, and lower legs in women.

Q: What causes malignant melanoma?

A: Uncontrolled growth of melanocytes.

Q: From what skin structure does malignant melanoma often develop?

A: Pre-existing moles.

Q: How common is malignant melanoma compared to other skin cancers?

A: It accounts for a smaller percentage of cases but is the most dangerous form.

Q: What age group is malignant melanoma most common in?

A: People aged 50–70.

Q: Why is malignant melanoma increasing worldwide?

A: Repeated exposure to sunlight (UV radiation).

Q: What visual changes in a mole may indicate malignant melanoma?

A: Changes in size, texture, or color; bleeding; fuzzy or irregular borders; asymmetry.

Q: What colors can malignant melanoma appear as?

A: Brown, black, blue, or red.

Q: What is the most common type of malignant melanoma?

A: Superficial spreading melanoma.

Q: Why is malignant melanoma considered highly dangerous?

A: It spreads rapidly (metastasizes) to other parts of the body.

Q: Which organs are commonly invaded when malignant melanoma metastasizes?

A: Liver, brain, and lungs.

Q: What is the most important factor for survival in malignant melanoma?

A: Early detection.

Q: What group of people has the strongest link to developing skin cancer?

A: Fair-skinned individuals.

Q: Approximately what percentage of fair-skinned people may develop skin growths related to skin cancer by age 70?

A: About 50%.

Q: How does UV radiation contribute to skin cancer?

A: It creates mutations in cells that allow them to escape normal cell cycle growth controls.

Q: What environmental factor is a major risk for melanoma?

A: Excessive sunlight exposure.

Q: Why is fair skin a risk factor for melanoma?

A: Fair skin burns easily and has less natural protection against UV radiation.

Q: How does family history affect melanoma risk?

A: A family history of melanoma increases the likelihood of developing it.

Q: How does having many abnormal moles affect melanoma risk?

A: Having a large number of abnormal moles (>6 mm) increases the risk.

Q: What medical treatment can increase the risk of melanoma?

A: Radiation therapy.

Q: What does the Fitzpatrick Scale measure?

A: Skin type based on how skin reacts to sun exposure (burning and tanning).

Q: What characterizes Fitzpatrick Skin Type I?

A: Skin burns very easily and does not tan; often associated with blonde or red hair.

Q: What characterizes Fitzpatrick Skin Type II?

A: Skin usually burns and has difficulty tanning.

Q: What characterizes Fitzpatrick Skin Type III?

A: Skin sometimes burns but gradually tans.

Q: What characterizes Fitzpatrick Skin Type IV?

A: Skin tans easily and rarely burns.

Q: What characterizes Fitzpatrick Skin Type V?

A: Skin tans without burning.

Q: What characterizes Fitzpatrick Skin Type VI?

A: Skin never burns and tans very quickly.

Q: What SPF level of sunscreen is recommended to help prevent skin cancer?

A: SPF 15 or greater.

Q: Which areas of the body should be especially protected with sunscreen?

A: Lips, ears, and face.

Q: Why should prolonged sun exposure be avoided?

A: It increases UV damage and risk of skin cancer.

Q: Why are blistering sunburns particularly dangerous?

A: They significantly increase the risk of skin cancer.

Q: What clothing can help reduce UV exposure?

A: Hats and protective clothing.

Q: During what time of day is sun exposure strongest and should be avoided?

A: Between 11 a.m. and 2 p.m.

Q: What does the ABCD rule help identify?

A: Warning signs of melanoma.

Q: What does “A” stand for in the ABCDs of melanoma?

A: Asymmetry.

Q: What does asymmetry in a mole indicate?

A: One half of the mole does not match the other, which may indicate melanoma.

Q: What does “B” stand for in the ABCDs of melanoma?

A: Border.

Q: What type of border may indicate melanoma?

A: Uneven, irregular, or fuzzy borders.

Q: What does “C” stand for in the ABCDs of melanoma?

A: Color.

Q: What color characteristics may indicate melanoma?

A: Two or more colors within the same mole.

Q: What does “D” stand for in the ABCDs of melanoma?

A: Diameter.

Q: What mole diameter may indicate melanoma?

A: Larger than 6 mm.

Q: What are typical characteristics of a benign mole?

A: Symmetrical shape, even borders, one color, and diameter less than 6 mm.

Q: What does the ABCDE rule help detect?

A: Warning signs of melanoma.

Q: What does “A” stand for in the ABCDE rule?

A: Asymmetry (one half of the mole does not match the other).

Q: What does “B” stand for in the ABCDE rule?

A: Border irregularity (uneven or jagged edges).

Q: What does “C” stand for in the ABCDE rule?

A: Color variation (multiple colors within the same mole).

Q: What does “D” stand for in the ABCDE rule?

A: Diameter larger than 1/4 inch (about 6 mm).

Q: What does “E” stand for in the ABCDE rule?

A: Evolution (changes in size, shape, or color).

Q: What are the typical characteristics of a normal mole using the ABCDE rule?

A: Symmetrical shape, even borders, one color, smaller than 1/4 inch, and remains unchanged.

Q: What is lentigo-solar?

A: An age-related skin disorder characterized by dark, irregular brown patches on the skin.

Q: What causes lentigo-solar?

A: Increased deposition of melanin due to increased proliferation of melanocytes.

Q: Where is lentigo-solar most commonly found?

A: Hands, face, and forearms.

Q: What is purpura?

A: Irregular purple-shaped patches on the skin caused by bleeding under the skin.

Q: What causes purpura patches to form?

A: Blood leaking from capillaries into surrounding tissue.

Q: Where does purpura most commonly appear?

A: On the limbs.

Q: What factors increase the risk of purpura?

A: Thin skin, steroid use, and blood-thinning medications.

Q: How does purpura differ from normal bruises during healing?

A: It does not go through the normal color-changing stages of bruising and can last for weeks.

Q: What is the primary cause of standard bruising?

A: Trauma that damages blood vessels under the skin.

Q: What causes purpura?

A: Leakage of blood from fragile capillaries.

Q: What factors increase the likelihood of purpura?

A: Aging, steroid use, and blood-thinning medications.

Q: How does the pathophysiology of bruising differ from purpura?

A: Bruising is caused by trauma to blood vessels, while purpura results from capillary fragility and leakage.

Q: What are cherry angiomas?

A: Elevated clusters of dilated or broken capillaries.

Q: What do cherry angiomas look like?

A: Small, bright red spots on the skin.

Q: Where do cherry angiomas most commonly appear on the body?

A: Most often on the torso, arms, and shoulders.

Q: What is the typical size of cherry angiomas?

A: About 1–4 mm.

Q: Are cherry angiomas medically serious?

A: No, they are clinically insignificant.

Q: How common are cherry angiomas in older adults?

A: About 75% of people over age 70 have them.

Q: What is an acrochordon?

A: A small skin growth known as a cutaneous skin tag.

Q: Where are acrochordons commonly found on the body?

A: Chest, neck, eyelids, and armpits.

Q: Which group commonly develops acrochordons?

A: Older women.

Q: What tissues make up an acrochordon?

A: Dermal connective tissue and blood vessels.

Q: What hormonal factor is thought to be associated with acrochordons?

A: Hormonal imbalances.