Skin cancer

Onc Pt. 4

Most common maligancy

Skin cancer

Melanin

pigment produced by melanocytes that make the color our skin & protects ahainst UV rays (tanned skin=response to sun damage)

Deadliest skin cancers

Merkle cell carcinoma & melanoma

Suspicious Moles (melanoma)

Assymetrical

Border irregularity

Color variation

Diameter greater than 6mm

Arises from melanocytes (pre-existing mole)

Melanoma

Melanoma prognosis

Poor

Most common melanoma histologic subtype (1/6)

Superficial spreading melanoma ( horizontal spread for years, then grow vertically)

Melanoma treatment

Surgery with wide local excision/removal of any affected lymph nodes

Radiation only for palliation of mets, adjuvant to surgery (reduce recurrence) or when surgery is not an option- not first line d/t radioresistant

Non-melanoma

Mostly arises from basal cell carcinoma & squamous cell carcinoma

Non-melanomas prognosis

better than melanoma

Non-melanoma that arises from stem basal cells

Basal Cell Carcinoma (BCC)

Most common skin cancer

Basal cell carcinoma

Basal cell carcinoma presentation

Pearly (shiny) smooth with telangiectasia, occurs on sun exposed areas

Basal cell carcinoma prognosis

Good, slow growing and doesn’t grow deeper than epidermis, so unlikely to metastasize

Squamous cell carcinoma vs Basal cell carcinoma

faster-growing & greater chance of metastasizing compared to BCC

Squamous cell carcinoma presentation

Crusty, Scaly lesions, occurs on sun exposed areas

Moh’s surgery

Removes tumor one layer at a time

treatment of BCC &SCC (non-melanoma)

Mohs surgery- especially squamous cell carcinoma (BCC can be removed in full in one excision as they are typically small & confined to epidermis)

Topical creams (5FU chemo)

RT-Mainly used on facial tumors where cosmetic results are important/ removal is difficult (electrons w/bolus to make field flat, kv x-tays, brachytherapy)

Merkel Cell Carcinoma

arises from Merkel cells- rare but very POOR PROGNOSIS, looks like pink-red nodular lesion with intact epidermis

Mycosis fungoides

looks like eczema but it’s T-cell non-Hodgkin lymphoma, use TBI electrons

Kaposi’s sarcoma

nodular purple/reddish lesions, common in those who have AIDS, rare & poor prognosis