benign and malignant facial skin lesions Flashcards
what is bowens disease
- classified as pre malignant lesion
- appear as red scaly patches
- is SCC in situ
risk factors for bowens disease
- chronic sun exposure
- previous RT tx
- HPV
tx for bowens
- excision
- freezing with liquid nitrogen
- 5- FU cream (chemotherapy cream)
what is xeroderma pigmentosum
- rare AR genetic disorder affecting skin, eyes, nervous system
- can have malignant changes to BCC and SCC
- patients have extreme sensitivity to sunlight
describe keratoacanthoma
dome shaped nodule with central keratin filled crater (keratinous plug)
risk factors for malignant lesions
- fair skinned
- prolonged solar exposure
- radiation
- atypical mole
- exposure to chemicals
typs of BCC
- cystic
- nodular
- morphemic
risk factors for BCC
- UV
- genetics
- men
- immune suppression
what are 2 types of tx of BCC
- surgical excision: safety margin, then direct closure, graft or flap
- Moh’s micrographic surgery: process whereby skin cells are removed in layers and checked
where does SCC originate from
originating from keratinizing or Malpighian cell layer of the epithelium
what is the safe margin for SCC
3-5mm beyond palpable margins
no need for prophylactic LN clearance
when do we use surgery and when do we use radiotherapy
surgery is generally for well differentiated tumors, RT is for poorly differentiated tumours
histopathological classification of melanoma - what 2 systems are used
- clark’s classification
- breslow thickness classification
what are the 2 phases of melanoma development
1) radial growth phase (still within the epidermis)
2) vertical growth phase (expands into papillary dermis)
syringomas are common in which areas of face
lower eyelid and upper cheeks
