Skin pathology III Flashcards
What causes a dermoid cyst
Incomplete separation of ectoderm and neuroectoderm during embryogenesis
What kind of cyst is a dilated pore of winer?
consisting of a large pore connecting with the epidermis
and irregular hyperplasia of the wall.
What is a sebaceous duct cyst?
cyst in the eye surrounded by hyperplastic sebaceous glands
What is a hamartomas?
benign growth that contains the same type of
cells that are normally found in the tissue where they grow.
What is a follicular hamartomas?
Cluster of large anagen hair follicles that extend more deeply than adjacent normal follicles
What is a fibroadnexal haematoma?
aggregates of distorted, variably inflamed
pilosebaceous units surrounded by dense collagen and
lacking a connection to the skin surface
What is a collagenous hamartoma?
a nodular accumulation of mature dermal collagen
What is a vascular hamartoma?
proliferation of small vessels,
may be misdiagnosed as hemangiosarcoma
What is a cutaneous horn?
a horn-like projection of the stratum corneum
What is glandular hyperplasia?
nodular accumulation of hyperplastic glands
What is a Fibroepithelial polyp also known as?
a skin tag
(mass of collagen covered in epidermis)
What causes a virally-induced papilloma?
papillomavirus in young/ immunodepressed animals
What is an equine sarcoid?
dermal proliferation with a pattern of fibroblasts caused by bovine papillomavirus
What is actinic keratosis?
epidermal hyperplasia and dysplasia of basal cell layer, increased mitoses.
What is an in-situ carcinoma?
neoplastic transformation of keratinocytes
does not invade the basement membrane.
What is a squamous cell carcinoma?
Dermal invasion of neoplastic keratinocytes with mitotic figures all levels of epidermis
What parts of the body does the squamous carcinoma usually effect?
Typically affect the sparsely haired and non-pigmented skin of ears and face (feline), penis and
prepuce (equine), conjunctiva (bovine and equine)
Where do tumours with adnexal differentiation arise from?
they arise from sebaceous or modified sebaceous glands
What breeds are genetically predisposed to dermoid cysts?
Rhodesian Ridgeback, Boxer
Where do follicular cysts originate from?
They originate from different portions of the hair follicle
What is a koliocyte?
swollen keratinocyte with a perinuclear halo
How may a squamous cell carcinoma arise?
UV-Induced mutation p53 -> pyrimidine dimers -> nucleotide repair pathway is overwhelmed
may be associated with a papilloma virus infection
What is a melanocytoma?
benign, circumscribed mass of heavily pigmented epithelial cells along the dermo-epidermal junction
