Approach to Lumps and Skin Tumours Flashcards
Define nodule…
A round solid elevation of the skin >1cm in diameter
What are the mechanisms of nodule formation?
Inflammation esp granulomatous
Neoplasia
Depositional disease
Trauma
Define panniculitis..
Inflammation of the subcutaneous fat and connective tissue
How do areas of urticaria react to pressure being applied?
They pit under pressure
How can inflammation cause urticaria?
Vasoactive mediators
Vessel permeability
Mast cells
Allergic
What are DDx for urticaria?
Dermatographism Heat/cold/exercise Drug reaction Contact urticaria Food/environmental allergy
What diagnostic tests are used in nodular disease?
FNA - cytology
Biopsy - histo, tissue culture
What can cause lump formation following trauma?
Bacterial or fungal infection
How are sebaceous or sweat gland tumours treated?
Lumpectomy
How are papillomatas treated?
Mostly resolve spontaneously
How are SCC treated?
Various specialist treatments available depending on affected areas:
Surgical resection of pinnae
Chemo of nose
Resection of nose
What are the 3 most common skin tumours in dogs?
MCT
Lipoma
Histiocytoma
What are the 3 most common skin tumours in cats?
Basal cell tumour
Fibrosarcoma
MCT
What are predisposing factors to developing skin cancer?
Sun exposure
Viruses
Genetics
Outline the workup of a skin tumour….
- Thorough Hx and PE
- FNA, biopsy
- Benign => therapeutics
- Malignant => FNA of local LN
- Imaging of thorax/abdomen
Which skin tumours require adjuvant anticancer therapy following surgery?
High grade MCT
Canine malignant melanoma
High grade FISS
How are cutaneous lymphomas treated?
Systemic anticancer medical therapy
What lesion appears similar to skin tumours but has a v good prognosis with surgery?
Cysts
What are the three types of skin cysts and where are they found?
Epidermoid - Extermities
Dermoid - Back, neck, scrotum
Follicular - Hair follicle
Name 4 types of epithelial tumours…
Papilloma
Basal cell carcinoma
Adnexal tumours
SCC
How are skin epithelial tumours treated?
Complete excision
Outline the characteristics of papillomas…
Dogs mostly
Viral in young dogs, resolves spontaneously
Pigmented plaques in older dogs, solitary and linked to SCC
Outline the characteristics of basal cell tumours…
Epithelioma or carcinoma Benign Common in cats Dome-shaped, hairless, unfixed to fascia Head, neck, shoulders Excision => good prognosis
Outline the characteristics of intracutaneous cornifying epitheliomas…
Benign Young dogs Mostly solitary Toothpaste material on rupture Excision => good prognosis
Outline the characteristics of hair follicle tumours…
Dogs
Mostly benign
Can originate from hair germ epithelium, follicular sheath or hair matrix
Breed predisposition
Outline the characteristics of sebaceous gland tumours…
Dogs mostly
Most commonly hyperplasia or epithelioma
Outline the characteristics of perianal/hepatoid gland tumours…
Sex hormones => modified sebaceous glands in perianal region
Intact male dogs
Castration can prevent recurrence or development
Mostly hyperplasia/adenomas
Breed disposition
Outline the characteristics of sweat gland tumours…
Apocrine cysts/adenomas found on head
Benign just require excision
ACA in cat>dog
Malignant require wide surgical excision
Outline the characteristics of apocrine gland anal sac adenocarinomas…
Solitary mass in anal sac
Diagnosed by cytology
Mostly metastatic
Stage using intrapelvic and iliac LN
Outline the characteristics of SCC…
Cats>dogs
Unpigmented skin
Nasal planum, eyelids, pinnae
Locally invasive but not metastatic
How are SCC treated?
Surgery
Radiotheraphy
Plesiotherapy (surface radiotherapy)
What are the most common round cell tumours?
Histiocytomas MCT Melanoma Cutaneous lymphoma Plasma cell tumour TVT
Outline the characteristics of cutaneous melanomas…
Dogs Mostly benign Diagnosed by FNA Histo required for prognosis Surgical excision => good prognosis
Outline the characteristics of canine MCT…
Common V variable appearance Diagnosis via FNA, prognosis via histo Graded by Patnaik system Surgical excision of tumour, local LN+/- radiation
Outline the Patnaik grading system
Patnaik grade + mitotic index = prognosis of MCT
I - low grade, MI <5
II - Intermediate
III - high, MI >5
What is involved in complete staging of a tumour?
Thorough Hx and PE
Palpation and FNA of local LN
Abdominal US and FNA of liver, spleen and enlarged LNS
Thoracic imaging
When is full staging of an MCT indicated?
Rapid growth, ulcerated LN metastasis Recurrent Systemic signs Unfavourable location Reconstructive/aggressive therapy is required Known high grade tumours
What should be done minimally in staging a MCT?
Full Hx and PE
Palpation and FNA of local LN
How is cutaneous lymphoma treated?
Lomustine
COP/COAP
Mastinib (KIT inhibitor)
