The lumpy horse Flashcards
what horses generally get melanomas
mostly grey horses
usually develop between 4-8 yrs
List the 4 types of equine melanoma
melanocytic nevi
dermal melanoma
dermal melanomatosis
malignant melanoma
what are the characteristic of melanocytic nevi
single or multiple discrete nodules
what are the characteristics of dermal melanoma
Originate in deeper dermis
Small singular or multiple nodules
what are the characteristics of dermal melanomatosis
Confluent large melanomas
Increased risk of metastasis
What are the charcteristics of malignant melanoma
Not common, invasive
In older horses
Recurrence very likely
List 4 typical locations of equine melanomas
Tail
Perineum
Parotid region
Commissure of lips/eyes
How to diagnose equine melanomas
Visual inspection
Palpation
Ultrasound
Fine needle aspiration
Decsribe anaplastic/ amelanotic malignant melanoma
Non grey and grey horses
Older horses
Tail and tailhead +++
Have metastasised by the time of diagnosis
Rare
List the key features of equine sarcoids
Benign
Non-metastatic
Locally aggressive
In all equids
High recurrence
List the 6 types of equine sarcoids
Occult
verrucose
nodular
fibroblastic
mixed
malignant
Describe occult equine sarcoids
occur in hairless skin
1 or more small (2-5 cm) cutaneous nodules
Mildest/most stable/superficial form of sarcoid
Describe verrucose sarcoids
Rarely aggressive
Rough hyperkeratotic appearance with some flaking or scaling
Warty-looking
Describe nodular sarcoids
Very variable sizes, 0.5 to 20 cm
Firm, spherical, subcutaneous nodules
Two types
What are the 2 types of nodular sarcoids
A: confined to subcutaneous tissues
B: some involvement of overlying skin
Describe fibroblastic sarcoids
Ulcerated, fleshy, aggressive appearance
2 types
Describe the 2 types of fibroblastic sarcoids
1: Pedunculated with limited/small base palpable under the skin
2: wide base, often diffuse/ill-defined margins
Decsribe malignant/ Malevolent sarcoids
Most severe, highly invasive- Infiltration of lymphatic vessels
Often following trauma or failed treatment
Cord of palpable tumour
Decsribe mixed sarcoids
Mixture of two or more types of sarcoid
Vary between verrucous/occult/nodular to fibroblastic
what is the most common skin cancer of horses
equine sarcoids
Describe transmission equine sarcoids
Not fully understood
possibly due to contact with sarcoids or contact with cattle/ horses carrying bovine papilloma virus
Decsribe the key features of equine squamous cell carcinoma
Locally invasive, does metastasise
List 5 predilections for squamous cell carcinomas
areas lacking pigmentation
poorly haired
mucocutaneous junctions
external genitalia
eye/adnexa
List 4 predisposing factors to equine squamous cell carcinomas
Equus Caballus papillomavirus 2 (EcPV2) and others
Flies
Smegma
Ultraviolet light exposure
Lust the 2 types of surgical excision of equine skin cancers
sharp excision
laser excision- currently favoured for sarcoid - and used a lot for melanoma
when can banding be used to treat sarcoids
only for sarcoids with a thin peduncle
Not to be used if the mass has a root
Takes a few weeks
when do we use topical chemotherapeutics for skin masses
for low mass burden only
DON’T use very close to eyes
Describe electrochemotherapy
uses electrical field pulses to induce increased cell membrane permeability to certain antitumour hydrophilic drug like cisplatin
List 2 topical chemotherapy creams
5-fluorouracil
Mitomycin C
List 4 drugs that can be used for intralesional chemotherapy
Mitomycin C
Tigilinol tiglate
5 Fluorouracil
Platinum- based e.g. cisplatin or Carboplatin
