Sarcoids And Melanoma Flashcards
What is a sarcoid?
Spontaneous, locally invasive, fibroblastic skin tumors
T/F: melanomas are the most common tumors on the horse
False
Sarcoids are the most common, melanomas are the 2nd most common
Predilection sites for equine sarcoids?
Head
Legs
Ventral abdomen
T/F: sarcoids are not metastatic but recurrence is very common
True
What causes equine sarcoids?
Bovine papilloma virus
What are the forms of equine sarcoids?
Fibroblastic (proud flesh-like)
Verrucous (warty)
Occult (slightly raised)
Combination of both
How do sarcoids appear histologically?
Hyperplasia and hyperkeratotic epidermis
Marked rete-peg formation
Irregularly arranged fibroblasts (whorls)
No invasion of underlying muscle
DDX for equine sarcoids?
Exuberant granulation tissue Fibrosarcoma Cutaneous habronemiasis Squamous cell carconoma Dermatophytosis (verrucous form)
Treatment for equine sarcoids?
Spontaneous regression
Surgical excision (laser or via scalpel)
Cryosurgery (tissue sloughs off and fills in with granulation tissue and epithelialization)
Chemotherapy (4 intratumoral injections of cisplatin given at 2 week intervals, mixed with sesame oil)
Radiation
Bacillus-Calmette-Guerin immunotherapy
What are melanomas?
Tumors arising from malignant transformation of melanocytes
Common signalment of horses with melanoma?
Gray horses
Older horses
Predilection sites for melanomas?
Perineal region Ventral tail Prepuce Head Neck Lips
Ears, spleen, lung, blood vessels
Possible clinical presentation of melanomas?
Darkly pigmented
Ulceration
Necrosis
Regional interference
Treatment of melanoma?
Surgery
Radiation
Intratumoral chemo or immunotherapy
Cimetidine
Cancer vaccine
How would you remove a melanoma on the border of the eyelid?
Sliding flap technique
Remove section of eyelid.
At base of flap, cut burows triangles allowing flap advancement
