SKIN CANCER
3 types of skin Ca
- Basal cell carcinoma (aka "epithelioma"): most common,
least aggressive--nearly 100% survival rate if tx'd
- Squamous cell carcinoma: intermediate in incidence and aggression; often
develops on old skin ulcerations; may be a sequela of Actinic
Keratoses
- Malignant melanoma: least common, most aggressive;
"Clark's" staging, I-V; mets to bone, lung,
liver, brain. In men us. on back, in women on legs.
Dark-skinned people rarely get melanoma, but when they
do, it's on less pigmented areas like ventral hands/feet,
and very aggressive. Staging system ("Breslow
Classification") depends on depth of skin
penetration by Ca. "Nonmalignant/Juvenile
Melanoma"--in kids/teens, who almost never get
malignant melanoma. Warning signs for jnal nevus
transforming to melanoma: getting darker, larger,
bleeding, itching
Etiology: sun exposure, arsenic (basal cell), therapeutic
radiation, persistent fistulae, chronic ulcers, e.g. from venous
stasis, chronic osteomyelitis
Treatment:
Basal--surgery, radiation, imiquimod, topical NSAIDs, topical 5-fluorouracil;
In a systematic review of 18 clinical trials on treatment of BCC, radiotherapy
c/w surgery was ass'd with sig. higher recurrence rate and sig. greater
long-term cosmetic defects over 4y (BMJ 329:705, 2004--JW)
Squamous--surgery
Melanoma--Local excision with/without LN resection