Approach to skin and soft tissue tumours Flashcards
Diagnosis of skin tumours
Cystology for some tumour types
Histopathology for definitive diagnosis
(Excisional/Punch biopsy)
Where is the most common site of neoplasia for the dog and cat
Skin
What does TNM mean when staging skin tumours
T Primary lesion - size and extent
N Regional /Sentinel node - palpate, image, aspirate
M Distant metastases - Xray, AUS, bloods
Treatment for local skin tumours
Surgery
Treatment for local and region lymph nodes
Surgery +/or radiotherapy
Treatment for multifocal diffuses skin tumour
Chemotherapy
Suggest causes of multiple skin lesions
Primary Cutaneous lymphoma (T cell)
Disseminated mast cell tumours
Histiocytic skin conditions
Hystiocytic
A group of rare disorders in which too many histiocytes (a type of white blood cell) build up in certain tissues and organs, including the skin, bones, spleen, liver, lungs, and lymph nodes.
Differentiate between cutaneous and systemic REACTIVE histiocytosis
Cutaneous histiocytosis = skin only
Systemic histiocytosis = skin, lymph nodes & other organs
Give examples of neoplastic histiocytic skin conditions
Histiocytic sarcoma (Malignant histiocytosis)
Haemophagocytic histiocytic sarcoma
Treatment for Reactive histiocytosis
Some may respond to immunosuppressive drugs (high dose corticosteroids, cyclosporine, tetracycline/niacinamide)
Give examples of epidermal solitary skin tumours
Papilloma
Basal cell tumour (Trichoblastoma or solid-cystic ductular sweat gland adenoma)
Squamous cell carcinoma
Give examples of dermal solitary skin tumours
Sebaceous and sweat gland adenoma/ACA
Hair follicle tumours (pilomatricoma/trichoepithelioma/trichoblastoma)
Give examples of Mesenchymal / subcut connective tissue
solitary skin tumours
Fibrous tissue (fibroma/sarcoma)
Adipose tissue (lipoma/sarcoma)
Are basal cell tumors more common in cats or dogs
In cats
Cause of Squamous cell carcinoma
Chronic exposure to UV light in depigmented skin (white) areas
Squamous cell carcinoma treatment
Treatment wide local surgical resection
What is the most common skin tumour of old dogs
Sebaceous gland tumours (hyperplasia-warts, cysts, adenoma, epithelioma)
Canine cutaneous histiocytoma signalment
up to 10% of all skin tumours
Young dogs < 5 yrs,
50 % in dogs < 2 yrs
Are majority of melanocytic tumours slow growing and benign?
85% are slow growing and benign
Signalment for mast cell tumours
Middle aged - older dogs
No sex predisposition
Breeds:
Boxers, Staff BTs, Boston Terriers
Labradors,
Golden Retrievers*
Weimeraners
Pugs
What is the name of the two systems used to predict mass cell tumour
Patnaik system (1984) - low, intermed, high grades
Kiupel system (2011)- low and high grade
Name mass cell tumour proliferation markers
Mitotic count (index)- no of mitoses/10 HPF
Ki67- nuclear stain for cells in cell cycle
AgNOR count- nuclear silver stain and PCNA (proliferating cell nuclear antigen)
cKI- Cell surface growth factor receptor with TK enzyme
What is the number of Mitotic count (index)- no of mitoses/10 HPF for a bad prognosis
> 5 mitoses/10HPF has worse prognosis
What is the percentage of Ki67 – nuclear stain for cells in cell cycle for a bad prognosis
1.8% of positive nuclei per total mast cells in field has a worse prognosis /decreased survival
What do granules in mast cell tumour contain
Histamine
Heparin
Vasoactive amines
What are the local effects of degranulation
Erythema
Swelling
Wheal formation- Raised, discolored blotch on the skin
‘Darier’s sign’- Urtication and erythematous halo that are produced in response to the rubbing or scratching of these lesions.
Systemic effects of hyperhistainaemia(paraneoplastic syndrome)
More likely with high grade tumour
Acts on H2 receptors in gastric parietal cells,leading to
- Increased acidity and motility
- Vomiting, anorexia, melaena
- Gastric ulceration
Treatment for Hyperhistaminaemia
Supportive therapy - fluids
H2 antagonists- Cimetidine, ranitidine, famotidine
Gastric protectants- Sucralfate (Antepsin)
Proton pump inhibitor- Omeprazole
Remove /treat mast cell tumour to remove source of histamine
Other biological effects of mass cell tumours
Hypotension
Coagulation problems– Localised haemorrhage
Delayed wound healing
Difference between low grade and high grade mast cell tumour ‘s effects of the body
Low grade - may have local effects
High grade - more likely to have systemic effects
High serum histamine reported with all grades
How do I diagnose a mass cell tumour
Do an FNA to confirm diagnosis (or biopsy)
Evaluate/FNA sentinel LN – for clinical stage
Difference between treatment of clinical stage 1 and 2 mass cell tumours
If Clinical Stage I (solitary mass and no sentinel LN mets)
- Surgical excision only – wide local excision or
- Marginal excision and radiotherapy or
- Radiotherapy alone if not amenable to surgery at all
If Clinical Stage II (solitary mass plus LN mets)
- As above and also LN excision / Radiotherapy
- Metastasis to LN implies higher grade, so chemotherapy as well
Give examples of drugs used in mass cell tumour chemotherapy
12 week Vinblastine/Pred protocol
Single agent Lomustine
Single agent TK inhibitor
What is the most common skin tumour in cat
Mass cell tumour
Signalment of feline mass cell tumours
Older cats (mean age 11years)
Siamese (Burmese, Russian Blue, Ragdoll) predisposed
List low grade sarcomas
peripheral nerve sheath tumor, haemangiopericytoma (cancer of capillary wall)
List medium grade sarcomas
Fibrosarcoma, myxosarcoma (neoplasm of connective tissue)
List high grade sarcomas
Haemangiosarcoma (neoplasm originating from the endothelial cells of the blood vessels) , Feline injection-site sarcomas, Histiocytic sarcoma
Outline sarcoma treatment
Chemotherapy as an adjunct to surgery for high grade tumours
Name drug name for sarcoma treatment
Doxorubicin based protocol for most sarcomas eg HSA (need care in cats eg FISS)
Lomustine for histiocytic sarcomas
What kind of tumour grades are FISS (Feline injection site sarcoma)
High grade
Treatment for feline injection site sarcoma
Surgery +/- radiotherapy for primary tumour
Chemotherapy for metastasis
Presentation of Haemangiosarcoma
- Superficial /soft tissue mass or haematoma
- Splenic Rupture- haemorrhage, collapse, abdominal distension, pale mmbs
- Cardiac signs- Muffled heart sounds, arrhythmias, Right sided Heart Failure
- Regenerative anaemia (blood loss, microangiopathic haemolysis), thrombocytopenia, neutrophilia, DIC
Treatment of Haemangiosarcoma
Primary tumour
- Surgical excision of subcutaneous mass
- Radical excision / amputation
- Splenectomy
- Pericardectomy
Metastasis
- Adjunctive chemotherapy
- Doxorubicin
- VAC
-Metronomic therapy
What is median survival time of splenic haemangiosarcoma
Surgery alone 1-3 months
Sx and Chemotherapy 5-7 months
What is median survival time of Intramuscular haemangiosarcoma
6-9 months with chemo
What is median survival time of skin haemangiosarcoma
Surgery alone
Dermal: 26-33 months (UV induced, thin coated dogs eg whippets, Pit Bulls
Subcutaneous: 7-10 months (39-40 mo in 1 study with adjuvant doxorubicin)
What is median survival time of cardiac haemangiosarcoma
3-4 months with Doxorubicin vs 12 days with no treatment
Outline the ‘T’ stage in TMN staging
Based off tumour diameter
T1-T4
T1: <2cm
T2: 2-5cm
T3: >5cm
T4: Invading muscle, bone etc
Outline the ‘N’ stage in TMN staging
N1,2: Ipsilateral or contralateral/bilateral LN
N3: Fixed nodes
Outline the ‘M’ stage in TMN staging
M1-Distant metastasis
Outline the WHO criteria for MCT staging
0: Incompletely excised tumour from dermis with no LN involvement
1: Single tumour in dermis without LN involvement
2: Single tumour in dermis with LN involvement
3: Multiple dermal tumours/ Large infiltrating tumours ± LN involvement
4: Any tumour with distant metastasis, blood or BM involvement
