Pathology Flashcards
(38 cards)
Localised overgrowth of blood vessels in the dermis =
Haemangiomas causes a port wine stain
melanoblasts migrate from neural crest to ++_
skin
uveal tract
leptomeninges
gene that determines balance of pigment in skin and hair
MC1R (melanocortin 1 receptor)
MC1R turns __ to __melanin
phaeo to eu
hair colour caused by phaeomelanin
red
1 defect in MC1R =
2 defects =
freckles
red hair and freckles
ephilides
freckles - patchy increase in melanin pigmentation
actinic/solar lentigines
age/liver spots
increased melanin and basal melanocytes
face, forearms and dorsal hands
elongated rete ridges in epidermis
acquired naevi in childhood = junctional naevus -
melanocytes proliferate and cluster at DEJ
acquired naevi in adolescence = compound naevus -
junctional clusters and groups of melanocytes in dermis
acquired naevi in adults = intradermal naevus -
no junctional activity, entirely dermal
dysplastic naevi 2 types =
increase in melanoma risk
sporadic - slight risk increase
familial - 100% increase risk
dysplastic naevi histological findings
architectuarl and cellular atypia
host-reaction inflam and fibrosis
epidermis not effaced (unlike melanoma)
characteristics of halo naevi
peripheral depigmented halo
inflammatory regression and overrun by lymphocytes
Blue skin pigmentation is caused by
brown deep in skin scatters light
blue naevi characteristics
entirely dermal and consist of pigment rich dendritic spindle cells.
Characteristics of spitz naevi
in <20yos
large spindle +/epithelioid cells
most entirely benign
rare sites for malignant melanoma
oesophagus meninges eye biliary tract anus
Radial growth phase of melanoma =
macules grow either entirely in situ or with dermal microinvasion
Vertical growth phase of melanoma =
invade dermis with formation of expansile mass with mitoses
only VGP metastasise
melanomas that have a radial and vertical growth phase (RGP and VGP)
superficial spreading
acral/mucosal lentiginous
lentigo maligna
melanoma type that only has a VGP (vertical growth phase)
nodular
common site of nodular melanoma
grows quickly in __ causing __ to stretch thin
trunk
dermis
epidermis stretched thin
suffix b added to staging of melanoma -
ulceration