Biopsy and histopathology
Taking a piece of the lesion or all of it and assessment of the tissue by a pathologist — the definitive diagnosis of the type of tumour, its grade and whether the margins are clear after surgery.
What it involves
Histopathological examination is the assessment of a tissue sample that has been fixed, cut into thin sections and stained — under the microscope the pathologist sees not only the cells but their arrangement, invasion of neighbouring tissues, blood vessels and the boundaries of the lesion. It is the “gold standard” for diagnosing a tumour: it determines the type and grade of malignancy (grading), and when the whole removed lesion is examined — whether the margin of healthy tissue is sufficient.
We collect material in several ways: punch biopsy (small skin “cores” a few millimetres in diameter), incisional biopsy (a piece of a larger tumour), excisional biopsy (the whole lesion) or core-needle biopsy of organs under ultrasound guidance. The choice depends on whether the diagnosis is to precede the operation or is its conclusion.
We send histopathology to a partner laboratory; the result usually arrives within 7–14 days. Where needed, we request additional tests (immunohistochemistry, margin assessment after additional staining) that refine the diagnosis and prognosis.
When it is used
When cytology is inconclusive or insufficient for planning (sarcomas, oral tumours, tumours of internal organs); before a major procedure whose extent depends on the type of tumour; and after every tumour removal — because without assessing the margins there is no way of knowing whether the operation was sufficient. We also examine lesions removed “incidentally” during another procedure, even when they look harmless.
Indications: symptoms that should prompt a visit
- Cytology of the lump did not give a clear answer.
- My dog has a hard, fixed lump under the skin that needs a major operation to be planned.
- My cat has a growth in the mouth or on the gum.
- A lump has been removed and I want to know whether it was excised completely.
- A skin lesion is not healing despite treatment and the vet wants to rule out a tumour.
- An ultrasound showed a lesion in the liver or kidney that cytology did not explain.
Conditions for which we use it in particular
Diagnostics beforehand
Before a biopsy we usually already have cytology and know where and how to collect the material so as not to complicate a later operation (important: the biopsy tract must be removed together with the tumour). We carry out a pre-sedation or pre-anaesthetic assessment (STD-01) with a blood count, platelets and biochemistry; for organ biopsies — clotting parameters and ultrasound.
How it proceeds
We perform punch biopsies of the skin under local anaesthesia or short sedation, with one or two sutures per wound; this takes about 15–20 minutes. Incisional biopsies of larger tumours and excisional biopsies are done under general anaesthesia with monitoring (STD-02) in the operating theatre, following the sterility protocol (STD-05). Organ biopsies under ultrasound are done under sedation, with observation after the procedure.
We label the specimen, mark the margins with ink (so that the pathologist knows where the cut edge was) and send it with a full clinical description — the quality of the description affects the quality of the answer. We discuss the result at a visit or by phone, recording the conclusions and plan in the medical records (STD-06).
Aftercare
After a biopsy: a collar or a body suit until the sutures are removed (10–14 days), keep the wound dry and clean, and give pain relief as scheduled. After an organ biopsy — a quiet day and observation; call if the animal becomes weak or turns pale.
We wait 7–14 days for the result; during this time we do not decide on further treatment unless the patient’s condition requires it. Once we have the result, we determine whether a repeat operation is needed (incomplete margin), whether further treatment is needed, or whether follow-up checks alone are enough.
Frequently asked questions
Wouldn't it be better to remove the whole lump straight away and send it for testing?
Sometimes, yes — with small skin lesions. With large or awkwardly placed tumours, an earlier diagnosis lets us plan the right margin and avoid a second operation.
How long does a histopathology result take?
Usually 7–14 working days, longer if additional tests are needed. We discuss the result as soon as we receive it.
What does “incomplete margin” mean?
That tumour cells reach the cut edge and part of the lesion may have been left behind. We then consider a wider re-excision of the scar or other treatment — we make the decision together.
Do you always send removed lumps for examination?
We recommend it every time, including for lesions that “look benign” — appearance can be misleading, and the result determines the follow-up checks.
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 biopsy and histopathological examination?
Call us or book a consultation. We will set out the diagnostic and treatment plan in writing, before you decide.