Week Seven - Basal Cell Carcinoma and Actinic Keratosis

Question 1

Why do basal cell carcinomas have a limited capacity to metastasize?

Answer 1

• Distant sites have an absence of necessary growth factors that are derived from the stroma of the original tumor site

Question 2

Where are the problem locations for BCCs?

Answer 2

• Around the eyes
• In the nasolabial folds
• Around the ear canal
• In the posterior auricular sulcus

Question 3

Persons aged 55-75 have a ____-fold higher incidence of BCCs than those younger than 20

Answer 3

• 100

Question 4

About ___% of patients who have had one BCC will develop another lesion within five years

Answer 4

• 40%

Question 5

What is the most important environmental risk factor for developing BCCs?

Answer 5

• Chronic ultraviolet radiation exposure

Question 6

What frequency and intensity of sun exposure increases the risk of BCC?

Answer 6

• Intermittent intense increments increases the risk of BCC more than a similar dose delivered more continuously over the same period of time

Question 7

Describe a “rodent ulcer”

Answer 7

• Nodular BCC with a center that ulcerates/bleeds and accumulates a crust/scale
• Ulcerated areas heal with scarring (patients assume their condition is improving because of episodes of healing)
• Cycle of growth, ulceration, and healing continues as the mass extends peripherally and deeper
• Lesions may become enormous

Question 8

Describe the borders of a morpheaform BCC and the associated difficulties

Answer 8

• The borders of a morpheaform BCC are indistinct and blend with normal skin making border localization of this tumor by inspection or biopsy impossible

Question 9

How do you treat a morpheaform BCC?

Answer 9

• Wide excision or Mohs micrographic surgery (preferable)

Question 10

Diagnosis of a BCC must be confirmed by ____

Answer 10

• Biopsy

Question 11

When should you treat BCCs, and why?

Answer 11

• BCCs must be treated early on to avoid the locally invasive, aggressive, and destructive effects on skin and surrounding tissue

Question 12

How does surgical excision of BCCs compare to ED&C and Mohs surgery?

Answer 12

• Surgical excision of BCCs is more effective than ED&C because there is better margin control, but has less effective margin control than Mohs surgery

Question 13

Why would one choose radiation therapy to treat a BCC?

Answer 13

• Noninvasive (relative sparing of critical structures)
• Relatively painless
• Good for patients who are not otherwise candidates for surgery
• High cure rate for selected lesions

Question 14

List three features of BCCs that account for a high likelihood for recurrence after initial treatment

Answer 14

• Locally invasive, aggressive, and destructive??

Question 15

How might sunlight exposure affect actinic keratoses?

Answer 15

• Existing AKs may become more active after sunlight exposure, but may undergo spontaneous remission if sunlight exposure is reduced

Question 16

Induration, inflammation, and oozing of an AK suggests ______ into ______

Answer 16

• Degeneration into malignancy

Question 17

AKs are most commonly confused with a ______ which has a “pasted-on” appearance

Answer 17

• Seborrheic keratosis

Question 18

How large of an area of AKs should be treated at one time using 5-FU? Why?

Answer 18

• Small regions should be treated at a time in those patients with extensive AKs due to the marked amount of inflammation that can occur when treating AKs with 5-FU

Question 19

Over time ____% of AKs may degenerate into SCCs

Answer 19

• 60%

Question 20

What basic principle does the Lazy S excision use?

Answer 20

• The Lazy S excision uses the basic principle of camouflaging a scar in cutaneous surgery by breaking up a straight line by using two curves.