Surgical oncology — removing tumours with a margin
Surgical removal of a tumour planned on the basis of the diagnosis and staging — with a margin chosen to suit the type of tumour, in two operating theatres with full monitoring and histopathological assessment of every lesion.
What it involves
Oncological surgery differs from “cutting out a lump” in that we plan it on the basis of knowing what the tumour is and how it behaves. Malignant tumours have projections beyond the outline of the lesion that are invisible to the naked eye, so we remove them with a margin of healthy tissue — from a few millimetres for benign lesions to 2–3 cm and one layer of fascia in depth for a mast cell tumour or sarcomas. The first operation is the most important: that is when there is the greatest chance of removing everything.
The scope of surgery includes tumours of the skin and subcutaneous tissue, the mammary gland (mastectomy), the spleen (splenectomy), oral tumours, the liver and the abdominal wall, as well as removal of affected lymph nodes. For extensive skin defects we use reconstructive techniques (advancement flaps) to close the wound without tension. Electrocautery reduces bleeding and the duration of the procedure.
We mark the margins of every removed lesion with ink and send it for histopathology — the result tells us whether the operation was sufficient or whether further treatment is needed.
When it is used
After the diagnosis has been established (cytology or biopsy) and the stage assessed, when the tumour is confined to a site from which it can be removed with an adequate margin without unacceptable disability. Also for palliative purposes — when removing an ulcerated, bleeding or painful tumour improves quality of life despite the presence of metastases; in that case we state this clearly as the aim of the procedure.
Bleeding from a ruptured splenic tumour requires emergency surgery during opening hours.
Indications: symptoms that should prompt a visit
- My dog has a mast cell tumour or sarcoma confirmed by cytology and needs excision with a margin.
- My bitch or female cat has mammary gland tumours.
- An ultrasound showed a splenic tumour or a single liver tumour without metastases.
- My cat or dog has a growth in the mouth that makes eating difficult.
- A skin tumour has ulcerated, is bleeding or the animal is scratching at it.
- After an earlier tumour removal, histopathology showed an incomplete margin and a repeat operation is needed.
Conditions for which we use it in particular
Diagnostics beforehand
Before the procedure: a cytological or histopathological diagnosis, staging (chest X-ray, abdominal ultrasound, lymph node cytology), pre-anaesthetic assessment according to STD-01 with a blood count, biochemistry and ASA grading, and echocardiography in senior animals and at-risk breeds.
How it proceeds
The patient arrives in the morning, fasted. After premedication and multimodal analgesia (STD-04, including local anaesthetic blocks) we induce general anaesthesia with monitoring of ECG, oxygen saturation, capnography, blood pressure and temperature (STD-02), with active warming. The surgical field includes the planned margin; before the operation begins, the team reads through the procedure checklist (STD-03). The procedure takes from 45 minutes for a single skin tumour to 2–3 hours for a unilateral mastectomy or splenectomy.
We remove the tumour in one piece without breaching its capsule, change instruments and gloves before closing the wound, and close the defect in layers, with a drain if needed. We label the specimen and send it for histopathology. The patient recovers from anaesthesia in the in-patient hospital with pain control; after skin procedures it goes home the same day, and after abdominal operations it usually stays 1–2 days — the lead veterinarian determines the scope of overnight supervision.
Aftercare
A collar or a body suit until the sutures are removed (10–14 days), keep the wound dry, with a check after 3 days and at suture removal; a drain, if placed, is removed after 2–4 days. Pain relief and, where prescribed, an antibiotic as scheduled, and restricted movement for 2 weeks, or 3–4 weeks after abdominal procedures.
We discuss the histopathology result after 7–14 days and then agree the next steps: check-ups every 3 months, a repeat operation if the margin is incomplete, or additional treatment. Call urgently if the wound opens, oozes or swells, or if the animal turns pale or stops eating.
Frequently asked questions
Why is the scar so large when the lump was small?
Because we remove not only the visible lump but also a margin of healthy tissue around and beneath it. A large scar is often the price of removing the tumour completely the first time.
Can a lump be removed without prior cytology?
For small, mobile skin lesions — yes, sending them whole for histopathology. For larger or suspicious ones, having a diagnosis beforehand makes it possible to choose the right margin.
What if histopathology shows that the margin was incomplete?
We discuss the options: wider re-excision of the scar, observation or additional treatment — depending on the tumour type and grade of malignancy.
Will an old dog tolerate such an operation?
Age is not a contraindication; what matters is the condition of the organs, assessed in the STD-01 pre-anaesthetic assessment and, where appropriate, a heart examination. We adapt the anaesthetic protocol to the patient.
We manage every case individually. The scope, indications and course described above are indicative; we agree the exact diagnostic and treatment plan during the consultation. This content is for information only and does not replace a veterinary consultation.
Do you have questions about oncological surgery?
Call us or book a consultation. We will set out the diagnostic and treatment plan in writing, before you decide.