Flashcards in Week 7 Deck (20)
Why do basal cell carcinomas have a limited capacity to metastasize?
Due to the absence of growth factors derived from the stroma of the original tumor site.
Problem locations for BCCs are around the eyes, in the nasolabial folds, around the ear canal, and in the posterior auricular sulcus
Persons aged 55-75 have a ______ -fold higher incidence of BCCs than those younger than 20.
Persons aged 55-75 have a 100-fold higher incidence than those younger than 20
About ____ percent of patients who have had one BCC will develop another lesion within five years
About 40% of patients who have had one BCC will develop another lesion within five years
What is the most important environmental risk factor for developing BCCs?
Chronic ultraviolet (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.
Describe a “rodent ulcer”
-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!
The borders of a morpheaform BCC are indistinct and blend with normal skin making border localization of this tumor by inspection or biopsy impossible
Treatment of morpheaform BCCs consists of wide excision or, preferably, Mohs micrographic surgery.
Diagnosis of BCC must be confirmed by ______________
BCCs must be treated early on to avoid the locally invasive, aggressive, and destructive effects on skin and surrounding tissues
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
ED&C= electrodesiccation and curettage
Why would one chose radiation therapy to treat a BCC?
-Noninvasive – relative sparing of critical structures
-Good for patients who are not otherwise candidates for surgery
-High cure rate for selected lesions
List three features of BCCs that account for a high likelihood for recurrence after initial treatment
size, borders, location???
Existing AKs may become more active after sunlight exposure and may undergo spontaneous remission if sunlight exposure is reduced.
Induration, inflammation, and oozing of an AK suggests _______________ into ______________
Induration, inflammation, and oozing suggest degeneration into malignancy
AKs are most commonly confused with a _________________ which have a “pasted-on” appearance
seborrheic keratosis (SK)
Because of the marked amount of inflammation that can occur when treating AKs with 5-FU, small regions should be treated at a time in those patients with extensive AKs.
Over time ____ % of AKs may degenerate into SCCs.