Follicular and adnexal tumors + more Flashcards
Virus associated with equine genital SCC
EcPV2
Virus associated with equine aural plaques
EcPV 3-6
Virus associated with feline skin papillomas
FcaPV1
Virus associated with deline oral papillomas
FcaPV2
What is the difference between BISC and SCC
BISC = dysplasia that stays within the epidermis and follicle
SCC crosses the BMZ, keratin pearls
Histopath characteristic finding for BISC
“Wind swept” look to basal cells without invasion into dermis
Which virus is most common in BISC in cats?
FcaPV2
(also 3-5 less commonly)
What is a risk factor for BISC, especially on haired, pigmented skin in cats?
FcaPV2
Characteristic histopath finding of SCC
Cords of dysplastic keratinocytes
Keratin pearls
IHC marker for SCC
Cytokeratin (epithelial)
Which virus is associated with SCC in horses?
EcPV2
Which virus is associated with SCC in cats
FcaPV2
What disease other than SCC has keratin pearls
Infundibular keratinizing acanthoma
But no atypical keratinocytes with IKA
T or F: Feline Basal Cell Tumors are often actinic
False. On haired skin.
Clusters of monomorphic basaloid cells
Most common type of hair follicle neoplasm in Guinea Pigs
Trichofolliculoma
Central depression or pore
Cystic primary follicle surrounded by secondary follicles
How can you differentiate follicular cyst types
Infundibular vs isthmus vs matrical vs hybrid
Which dog breed may be predisposed to tricholemmoma
Afghan hounds
Origin of tricholemmoma
Derived from ORS
“Bulb cells” lined by thick, hyalinized basement membrane
Trichoepithelioma biologic behavior
Benign
What cat breed is predisposed to trichoepitheliomas
Persians
Histopath of trichoepithelioma
Cystic islands of epithelium with hair follicle differentiation
Looks like little bulbs within the dermis
IHC marker for trichoepithelioma
p27
(Also trichoblastoma!)
Which 2 hair follicle tumors are + for p27
Trichoblastoma
Trichoepithelioma
Which hair follicle tumor is common in cats and dogs
Trichoblastoma
Base of the ear; BENIGN
Origin of trichoblastoma
Hair germ
Low proliferative capacity –> BENIGN
Infundibular keratinizing acanthoma (keratoacantoma) breeds
Norwegian elkhound
Keeshonds
GSD
English SHeepdogs
Collies
Lhasa apsos
Yorkie
Histopath of infundibular keratinizing acanthoma
Cup shapred
Several keratin pearls on periphery (secondary cysts)
What is this (older cat on head, neck or trunk)
Dilated pore of Winer
Benign. Large central pore with keratin
Clinical lesion: Dog. Solitary, wartlike papules/nodules with hyperkeratotic umbilicated center
On histopath: cup-shaped invagination, keratin filled channel connects to surface.
At center of invagination– acantholytic dyskeratotic cells, corps ronds
Warty Dyskeratoma
benign
Other name for Calcifying epithelioma
Pilomatricoma
Origin of pilomatricoma
Follicular bulb
Breeds predisposed to pilomatricomas
Kerry blue terriers
Poodles
Old English Sheepdogs
T or F: the basal cells that make a pilomatricoma have LOW p27, resulting in a HIGH mitotic rate
True.
Tumor can grow quickly
Which tumor is LOW in p27
Pilomatricoma
Order of most common to least common sebaceous gland tumors
1) Nodular hyperplasia
2) Sebaceous epithelioma
3) Sebaceous adenoma
4) Sebaceous adenocarcinoma
Breeds predisposed to sebaceous hyperplasia
Beagle
Cocker spaniel
Poodle
Dachshund
Mini schnauzer
Difference between sebaceous gland hyperplasia and sebaceous adenoma
Adenoma has more lobule proliferation, more irregularity in shape/size
More likely to form DUCTS than hyperplasia
Breeds predisposed to sebaceous epitheliomas
Shih tzus
Lhasa apsos
Malamutes
Huskies
Irish Setters
Color of sebaceous epitheliomas
Oftentimes melanocytic
Eyelids, head
Biologic behavior of sebaceous epitheliomas
Low grade malignancy
Technically a basal cell carcinoma with sebaceous differentiation
Sebaceous adenocarcinoma frequency in dogs and cats
RARE
Only 2% of sebaceous tumors
Body region most likely to have a sebaceous adenocarcinoma
Head, limbs
Ulcerate
What type of gland are perianal glands
Modified sebaceous glands
What hormones do perianal glands respond to
Androgen and estrogen receptors on perianal glands
Breeds predisposed to perianal gland tumors
Cocker spaniel
English Bulldog
Samoyed
Afghan
Dachshund
GSD
Beagle
Husky
Shih tzu
Lhasa apso
Which sex is more likely to have a perianal glands adenoma
MALES
9x more frequent in M than F
Neuter
Treatment for perianal gland adenoma
Neuter resolves perianal gland adenoma in 95% of cases
Biological behavior of perianal gland carcinoma
Metastasis in 30%
Dogs with tumors >5 cm have worse prognosis
What type of gland is a ceruminous gland
Apocrine
Synonym for apocrine gland
Epitrichial
Synonym for eccrine gland
Atrichial sweat gland
Most common location of atrichial sweat gland tumors
Paw pads
Which animal is more likely to have an apocrine gland tumor
Cats > dogs
(think ceruminous cystomatosis)
Head/neck
Black/purple color from secretions
Labwork finding common with AGASACA
Hypercalcemia (PTHrp)
25-50% of dogs
Breed (Cat) with apocrine sweat gland carcinomas
Siamese
What is the most common cutaneous neoplasm in pigs
Melanomas. BENIGN, spontaneously regress
EXCEPTION:
Familial in Sinclair pigs —> metastasis common
Which breed of pig is predisposed to metastatic cutaneous melanomas
Sinclair pigs
Melanoma
Which body sites are associated with a higher rate of metastasis for melanoma?
Digital
Mucocutaneous
Which breeds are predisposed to subungual melanomas
Scottish terrier
Irish setter
Schanuzers
IHC markers for melanomas
Melan A
PNL2
TRP-1
TRP-2
T or F: Melanomas on the eyelids are likely to metastasize
False. Skin and hair rarely metastasize
Dog breed that develops FIbropruritic nodules 2’ FAD
GSD. Occur on caudal dorsum
2 causes for fibrosarcomas in cats
1) FeLV
2) Post vaccine
Legs, pinnae
IHC stain for fibrosarcomas
Vimentin (mesenchymal cell)
Breeds predisposed to fibrovascular papillomas
Large and giant breeds (Dobermans, labradors)
May be proliferative response 2’ trauma
Possible cause of fibrovascular papillomas in Dobies, Labs
Proliferative response 2’ trauma
IHC marker for hemangioma
Vimentin, factor VIII-related antigen, Type IV collagen, laminin
In dogs: are hemangiomas or hemangiosarcomas more common
Hemangiomas
Actinic cause
In cats: are hemangiomas or hemangiosarcomas more common
Hemangiosarcomas
Actinic cause
Better prognosis if dermal only (than SC, IM)
IHC markers for hemangiosarcoma
Sarcoma only: CD31 (PECAM), S-110
Same as hemangioma: Vimentin, Factor VIII-related antigen, type IV collagen, laminin
Location of hemangiosarcomas on cats
Head, pinnae
Location of hemangiomas on dogs
Trunk (actinic)
Extremities (not actinic)
Body sites for lymphangiomas
Axillae, inguinum
Fluctuant swelling full of milky fluid
Body sites for lymphangiosarcomas
Ventral abdomen, limbs
Biologic behavior of lymphangiosarcoma
AGGRESSIVE
Can occur in young dogs, cats
Clinical sign of lymphangiosarcoma
Fluctuant swelling with pitting edema, lymphorrhea, purpura
IHC markers for lymphangiosarcoma
PROX1
LYVE1
Vimentin
Predisposed breed to feline MCT
Siamese
Sex for feline MCT
Male cats
Type for MCT form seen in siamese cats
Histiocytic form
Can spontaneously regress
Which type of tumor has a Grenz zone
Plasmacytoma
helps differentiate from histiocytoma
How do histiocytomas regress?
CD8+ lymphocytes infiltrate from the bottom
Necrosis 2’ cel mediated immunity
IHC for histiocytoma (LC origin)
CD11c/CD18
CD1a+
E-cadherin
IHC for cutaneous reactive histiocytosis
NO E-CADHERIN (dif than histiocytoma)
Thy-1
CD4
Cell origin of feline progressive histiocytosis
Dendritic cell origin
IHC for feline progressive histiocytosis
CD1a
CD11c
CD18
MHC cl II
Most common type of cutaneous lymphoma in horses
T cell rich B cell lymphoma
Treatment TVT
Vincristine
Gene, Mode of inheritance of GSD Nodular dermatofibrosis
FLCN, autosomal dominant
Signalment calcinosis circumscripta
Younger dogs
Large breed
Likely relate to trauma
Stains for calcinosis circumscripta
PAS
Alcian blue
Gene, mode of inheritance for Dermoid Cysts
FGF 3, 4, 19
Autosomal recessive
Dorsal midline
Clinical lesions of lichenoid keratosis
Erythematous hyperkeratotic plaques on pinnae, groin of adult dogs
Seborrheic keratosis/ sebacous nevi clinical lesions
Plaques, nodules
Greasy, hyperkeratotic surface
Causes of cutaneous horn
SCC
Keratinaceous cyst
IKA
Actinic keratosis
Basal cell tumor
Papillomavirus
CHECK FELV STATUS
Feline papillomavirus strains associated with Viral Plaques, BISC, and SCC
FcaPV 2, 3
Equine sarcoid oncoproteins
E5, E6, E7
T or F: BPV1, 2 has been found in healthy equine skin
True
Protein associated with INVASIVENESS of equine sarcoid
MMP-1, 2, 3
Is DNA methylation increased or decreased in equine sarcoids
Increased DNA methylation
Breeds with equine sarcoid
Quarter horses, Franches-Montagnes > thoroughbreds > standardbreds
Which fly MAY be associated with equine sarcoid
Stomoxys calcitrans
More sarcoid in horses stabled near cattle
T or F: VEGF, PDGFb, FoxP3 are associated with equine sarcoid
True
Name the 6 categories of equine sarcoid
1) Occult
2) Verrucous
3) Nodular
4) Fibroblastic
5) Mixed
6) Malignant
Body regions most commonly affected with occult equine sarcoid
Hairless body sites
(Perioral, periocular, neck, medial limbs)
Most common body sites for nodular equine sarcoids
Groin, sheath, eyelid
Type 1 vs Type 2 Fibroblastic equine sarcoids
Type 1: Pedunculated base
Type 2: Broad based (sessile)
Associated with trauma
Horse plaque
Equine sarcoid
- Picket fence neoplastic cells at DE junction
- Increased fibroblasts
- Hyperplastic epidermis with rete peg-like structures
Malignant equine sarcoid clinical lesion
Most severe
Invasive/destructive
Infiltration of lymphatic vessels – can palpate chords of tumor in lymphatics
T or F: Histopath can distinguish between different sarcoid types
False. Clinical distinction
CANNOT RELY ON HISTO TO PREDICT BIOLOGIC BEHAVIOR
3 breeds with hereditary multifocal digit SCC
1) Black standard poodle
2) Giant schnauzer
3) Bouvier Des Flandres
(all black dogs)
Genes:
MC1R
KITLG
Biologic behavior of trichoepithelioma vs sebaceous epithelioma
Trichoepithelioma: benign
Sebaceous epithelioma: low grade malignancy