Principles of Surgical Oncology. Winnie Achilles Tierklinik Hollabrunn Lastenstrasse Hollabrunn

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1 Principles of Surgical Oncology Winnie Achilles Tierklinik Hollabrunn Lastenstrasse Hollabrunn boexi@gmx.de

2 The first surgery provides the best chance for a cure in an animal with a tumor

3 Clinical examination general health status neoplastic paraneoplastic syndromes e.g., cancer cachexia comorbid conditions. e.g., renal failure, congestive heart failure Findings may influence the selection of management options anesthetic and surgical management aftercare

4 Age Tumours are more commonly diagnosed in older animals But: Malignant tumours in younger animals tend to have a more aggressive biologic behaviour (undifferentiated malignant oral tumours in dogs, renal nephroblastoma, canine appendicular osteosarcoma)

5 What is the biological behavior of the tumour? benigne or malignant infiltrative or well encapsulated Distant metastatic disease

6 Staging Tumour type Metastatic disease Concomitant disease characteristics of the primary tumor are important for clinical staging and may assist in determining treatment options and prognosis lymph node biopsy to determine whether the lymph node is reactive or metastatic.

7 Skin Masses 25%-30% of all tumours in dogs arise from the skin 70% of these being benign (cysts, lipoma, sebaceous gland hyperplasia/adenoma, histiocytoma) Histiocytoma

8 Malignant skin tumours mast cell tumour basal cell tumour squamous cell carcinoma fibrosarcoma Mostly in cats and dogs older than 10 years exception: MCT

9 Biopsy Results influencing treatment options, the extend, and the willingness to treat Biopsies are not indicated- If the biopsy carries the same risk as the definitive surgery (brain or spinal cord tumour, isolated lung mass) Does the biopsy correlate with the clinical presentation?

10 Biopsy Technique FNA, needle-core biopsy, incisional biopsy, and excisional biopsy ideal biopsy technique should simple and safe procedure result in an accurate diagnosis the same instruments should not be used to sample multiple masses due to the risk of contamination

11 Fine Needle Aspiration - Cytology Easy and economical to perform on cutaneous and subcutaneous lesions Overall accuracy rates range from 64% to more than 90% sensitivities from 64% to 96% specificities From 65% to 100%

12 Fine Needle Aspiration - Cytology differentiation of nonneoplastic from neoplastic diseases classifies tumours as round cell epithelial cell or mesenchymal cell may require US or CT for accurate aspiration from within body cavities retrobulbar space thoracic cavity abdominal cavity

13 Consider alternatives to cytology if: Transitional cell carcinoma no percutaneous cystocentesis due to the risk to spread neoplastic cells -perform an urethral wash Liver mass - cytology often not diagnostic due to blood contamination Haemoabdomen, splenic mass result will not change treatment options Should the cytology have failed to diagnose the tumour

14 TruCut needle-core biopsy provides a small volume of tissue for impression smears or histopathology diagnostic accuracy between 96% and 100% accuracy Sedation or local anesthesia is usually required complications fistula formation, hemorrhage, infection, and tumour seeding vagal shock

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16 Incisional biopsy Incisional biopsy techniques which include surgical wedge and punch biopsy are recommended for soft, friable, inflamed, and necrotic tumors peripheral lymph nodes should include a junction between normal and abnormal tissue But: Tumour tissue is often awkward to suture, is brittle and well vasculised Do not place drains

17 Excisional biopsy Has the potential to combine both diagnosis and therapy in a single procedure Indications: brain or spinal cord tumour, isolated lung mass, splenic tumour Is not recommended for most skin or subcunaneous tumours like feline vaccine associated sarcoma or mast cell tumour

18 Diagnostic Imaging to describe the extent of the local tumour presence of regional and distant metastatic disease Modality of imaging depends on the type of tumour 3 plane thoracic radiographs for osteosarcoma or haemangiosarcoma but abdominal ultrasound for MCT or histiocytic sarcoma

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21 Ultrasonography Abdomen Cardiac neoplasia chemodectoma, atrial haemangiosarcoma To assess tumour vascularity

22 Computer Tomography does provide accurate three-dimensional information about tumour location for CT-guided biopsy radioablation surgical resection

23 Can show metastatic lesions as small as 1 mm Contrast agent can highlight neoplasms

24 Magnetic Resonance Imaging (MRI)

25 Lymph Node Staging Palpate regional lymph nodes for enlargement, asymmetry, and degree of fixation FNA or Biopsy The sentinel lymph node concept in human oncology In one study of 100 dogs with oral malignant melanoma, 40% of dogs with normal-sized lymph nodes had metastases 49% of dogs with enlarged lymph nodes did not

26 WHO classification scheme for tumours in domestic animals

27 radical, wide, marginal resection, debulking

28 Use different instruments for the clean or dirty side of the procedure

29 Make a plan! Wide aseptical preparation

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41 biopsies should be fixed in 10% buffered formalin

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44 Questions?