Approach to Lumps and Skin Tumours

Question 1

Define nodule…

Answer 1

A round solid elevation of the skin >1cm in diameter

Question 2

What are the mechanisms of nodule formation?

Answer 2

Inflammation esp granulomatous
Neoplasia
Depositional disease
Trauma

Question 3

Define panniculitis..

Answer 3

Inflammation of the subcutaneous fat and connective tissue

Question 4

How do areas of urticaria react to pressure being applied?

Answer 4

They pit under pressure

Question 5

How can inflammation cause urticaria?

Answer 5

Vasoactive mediators
Vessel permeability
Mast cells
Allergic

Question 6

What are DDx for urticaria?

Answer 6

Dermatographism
Heat/cold/exercise
Drug reaction
Contact urticaria
Food/environmental allergy

Question 7

What diagnostic tests are used in nodular disease?

Answer 7

FNA - cytology

Biopsy - histo, tissue culture

Question 8

What can cause lump formation following trauma?

Answer 8

Bacterial or fungal infection

Question 9

How are sebaceous or sweat gland tumours treated?

Answer 9

Lumpectomy

Question 10

How are papillomatas treated?

Answer 10

Mostly resolve spontaneously

Question 11

How are SCC treated?

Answer 11

Various specialist treatments available depending on affected areas:
Surgical resection of pinnae
Chemo of nose
Resection of nose

Question 12

What are the 3 most common skin tumours in dogs?

Answer 12

MCT
Lipoma
Histiocytoma

Question 13

What are the 3 most common skin tumours in cats?

Answer 13

Basal cell tumour
Fibrosarcoma
MCT

Question 14

What are predisposing factors to developing skin cancer?

Answer 14

Sun exposure
Viruses
Genetics

Question 15

Outline the workup of a skin tumour….

Answer 15

1. Thorough Hx and PE
2. FNA, biopsy
3. Benign => therapeutics
4. Malignant => FNA of local LN
5. Imaging of thorax/abdomen

Question 16

Which skin tumours require adjuvant anticancer therapy following surgery?

Answer 16

High grade MCT
Canine malignant melanoma
High grade FISS

Question 17

How are cutaneous lymphomas treated?

Answer 17

Systemic anticancer medical therapy

Question 18

What lesion appears similar to skin tumours but has a v good prognosis with surgery?

Answer 18

Cysts

Question 19

What are the three types of skin cysts and where are they found?

Answer 19

Epidermoid - Extermities
Dermoid - Back, neck, scrotum
Follicular - Hair follicle

Question 20

Name 4 types of epithelial tumours…

Answer 20

Papilloma
Basal cell carcinoma
Adnexal tumours
SCC

Question 21

How are skin epithelial tumours treated?

Answer 21

Complete excision

Question 22

Outline the characteristics of papillomas…

Answer 22

Dogs mostly
Viral in young dogs, resolves spontaneously
Pigmented plaques in older dogs, solitary and linked to SCC

Question 23

Outline the characteristics of basal cell tumours…

Answer 23

Epithelioma or carcinoma
Benign
Common in cats
Dome-shaped, hairless, unfixed to fascia
Head, neck, shoulders
Excision => good prognosis

Question 24

Outline the characteristics of intracutaneous cornifying epitheliomas…

Answer 24

Benign
Young dogs
Mostly solitary
Toothpaste material on rupture
Excision => good prognosis

Question 25

Outline the characteristics of hair follicle tumours...

Answer 25

Dogs Mostly benign Can originate from hair germ epithelium, follicular sheath or hair matrix Breed predisposition

Question 26

Outline the characteristics of sebaceous gland tumours...

Answer 26

Dogs mostly | Most commonly hyperplasia or epithelioma

Question 27

Outline the characteristics of perianal/hepatoid gland tumours...

Answer 27

Sex hormones => modified sebaceous glands in perianal region Intact male dogs Castration can prevent recurrence or development Mostly hyperplasia/adenomas Breed disposition

Question 28

Outline the characteristics of sweat gland tumours...

Answer 28

Apocrine cysts/adenomas found on head Benign just require excision ACA in cat>dog Malignant require wide surgical excision

Question 29

Outline the characteristics of apocrine gland anal sac adenocarinomas...

Answer 29

Solitary mass in anal sac Diagnosed by cytology Mostly metastatic Stage using intrapelvic and iliac LN

Question 30

Outline the characteristics of SCC...

Answer 30

Cats>dogs Unpigmented skin Nasal planum, eyelids, pinnae Locally invasive but not metastatic

Question 31

How are SCC treated?

Answer 31

Surgery Radiotheraphy Plesiotherapy (surface radiotherapy)

Question 32

What are the most common round cell tumours?

Answer 32

``` Histiocytomas MCT Melanoma Cutaneous lymphoma Plasma cell tumour TVT ```

Question 33

Outline the characteristics of cutaneous melanomas...

Answer 33

``` Dogs Mostly benign Diagnosed by FNA Histo required for prognosis Surgical excision => good prognosis ```

Question 34

Outline the characteristics of canine MCT...

Answer 34

``` Common V variable appearance Diagnosis via FNA, prognosis via histo Graded by Patnaik system Surgical excision of tumour, local LN+/- radiation ```

Question 35

Outline the Patnaik grading system

Answer 35

Patnaik grade + mitotic index = prognosis of MCT I - low grade, MI <5 II - Intermediate III - high, MI >5

Question 36

What is involved in complete staging of a tumour?

Answer 36

Thorough Hx and PE Palpation and FNA of local LN Abdominal US and FNA of liver, spleen and enlarged LNS Thoracic imaging

Question 37

When is full staging of an MCT indicated?

Answer 37

``` Rapid growth, ulcerated LN metastasis Recurrent Systemic signs Unfavourable location Reconstructive/aggressive therapy is required Known high grade tumours ```

Question 38

What should be done minimally in staging a MCT?

Answer 38

Full Hx and PE | Palpation and FNA of local LN

Question 39

How is cutaneous lymphoma treated?

Answer 39

Lomustine COP/COAP Mastinib (KIT inhibitor)