Skin cancer Flashcards
BCC histology
basaloid appearance of the epithelial islands = pathognomonic
cells mimic germinative epithelium and have an increased N:C ratio
show peripheral palisading, in which they are arranged perpendicular to the BM
tumour has a characteristic invasive pattern with formation of large islands, cords, and teardrops
cells w/in the centre of the epithelial islands have nondiscrete cytoplasmic borders and mimic syncytium
stomas show varying amounts of collagen deposition with abundant mucin
BCC clinical features
usually look like a raised, smooth, pearly bump on the sun-exposed skin of the head, neck, or shoulders
Small blood vessels may be visible within the tumour
central depression with crusting and bleeding frequently develops
often mistaken for a sore that doesn’t heal
BCC tx
surgery (simple excision/micrographic) curettage & electrodessication cryosurgery radiotherapy topical 5-FU (multiple superficial BCC on trunk/lower limbs)
Actinic keratosis histology
epidermal changes characterized by acanthosis and dyskeratosis
keratinocytes vary in size and shape, many have mitotic figures
marked hyperkeratosis and areas of parakeratosis with a loss of the granular layer
dense inflammatory infiltrate may be present
Actinic keratosis clinical features
pink scaly patch on areas of maximal sun exposure, limited to the epidermis
Actinic keratosis treatment
cryosuerger
curettage
topical 5-FU
photodynamic therapy
SCC histology
Intraepidermal SCC characterized by full-thickness epidermal atypia (cellular atypia, loss of polarity, pleomorphic and/or hyperchromatic nuclei, mitotic figures, parakeratosis)
Invasive SCC present when cellular atypia penetrates the epidermal BM
SCC Clinical features
commonly a well-defined, scaly, hard pink or white nodule, on sun-exposed skin
Similar to BCC, ulceration and bleeding can occur
SCC Tx
surgery curretage & electrodessication cryosurgery radiotherapy carbon dioxide laser
Atypical nevi histology
superimposed upon those of a typical junctional or compound nevus, including:
- melanocytes along the basal layer, with elongation of rete ridges
- cytologic atypia of melanocytes with enlarged, hyperchromatic nuclei randomly scattered in the junctional component
- horizontal arrangemetn of melanocytes which vary in shape
- tendency for melanocytes to aggregate into nests which fuse with adjacent rete ridges
- presence of lamellar and concentric dermal fibroplasias
- presence of a lymphocytic infiltrate in the superficial dermis
- extension of the junctional component
Atypical nevi clinical features
show considerable variation in edge and colour
tend to remain flat and youthful
extend sideways to a size typically in excess of 6 mm = inability to mature properly
Atypical nevi treatment
close examination/observation
surgical removal and biopsy
Melanoma histology
superficial spreading melanoma, lentigo maligna melanoma and acral lentiginous melanoma have an in situ (radial growth) phase characterized by increased numbers of intraepithelial melanocytes
- large and atypical
- arranged haphazardly at the dermal-epidermal junction
- show upward (pagetoid) migration
- lack the biologic potential to metastasize
Eventually, the growth pattern assumes a vertical component and grows downward into the deeper dermal layers and gains metastatic potential
Melanoma clinical features
majority are brown-to black-pigmented lesions Warning signs: changes in - size - shape - colour - elevation
Melanoma tx
primary tumour removed with resection margins depending on the tumour thickness (1 mm - 2-3 cm margin)
treatment of metastases require surgery if possible, radiotherapy and chemotherapy (not very effective)
