Diagnostics: Incisional Biopsy
An incisional biopsy removes a small part of an abnormal area in the mouth, throat, skin, or neck so it can be examined under a microscope while the rest is left in place.
What an incisional biopsy is
An incisional biopsy is a procedure that removes only a small piece of an abnormal area (a lesion, lump, or mass) so it can be examined under a microscope. The word "incisional" means a cut is made to take a sample, but the whole abnormality is deliberately left in place. The goal is to make a diagnosis first, before deciding on any larger treatment.
Taking a representative sample rather than the entire lesion has an important advantage: it preserves the size, shape, and borders of the abnormality. That information can be valuable when planning definitive treatment later.
How it differs from other biopsies
The main types of biopsy differ in how much tissue is removed and how it is obtained:
Excisional biopsy removes the entire lesion, usually with a rim of normal-looking tissue around it. It is generally chosen for smaller lesions, where taking everything can be both diagnostic and, in some cases, treatment. An incisional biopsy, by contrast, removes only part of a lesion and is generally chosen when the abnormality is larger or when a diagnosis is needed before more extensive surgery.
Needle biopsy uses a hollow needle passed through the skin to withdraw either a tiny cluster of cells (fine-needle aspiration) or a thin core of tissue (core needle biopsy). It is less invasive than an incisional biopsy and often does not require a skin cut or stitches, but it provides a smaller sample. More detail is available on the page about needle biopsy.
Punch biopsy uses a small round, cookie-cutter-like blade to remove a deep but narrow cylinder of tissue. A punch can serve as an incisional biopsy (sampling part of a large lesion) or, if the whole lesion is smaller than the punch, as an excisional biopsy. In other words, whether a biopsy is "incisional" or "excisional" is determined by how much of the lesion is removed, not by the specific instrument used. See also the page about punch biopsy of the skin.
When an incisional biopsy is used
An incisional biopsy is typically chosen when:
The abnormal area is too large to remove completely without first knowing what it is.
A diagnosis is needed to plan the right operation or treatment.
Simpler or less invasive tests (such as a needle biopsy) did not provide a clear answer.
The depth of the abnormality or the way it is arranged in the tissue needs to be assessed, which requires a fuller-thickness sample than surface scrapings can give.
Where it is performed and what the setting looks like
Incisional biopsies are done in different parts of the body, and the setting depends on the location and how easy the area is to reach:
Inside the mouth (oral): A small piece of an abnormal patch or growth on the gums, tongue, cheek lining, or palate is removed, often with a scalpel or a punch. Many oral biopsies are done in an office or clinic with numbing medicine; larger or harder-to-reach lesions may be done in an operating room. Related information is available on oral tumors, growths, and bumps.
In the throat: Abnormalities at the base of the tongue, tonsils, or throat wall are often deeper and harder to see. These biopsies are frequently performed in an operating room during an "examination under anesthesia," where the surgeon uses special instruments to view and sample the area. See also throat tumors.
On the skin: A piece of a large skin lesion is removed, commonly using a scalpel or punch, usually in an office or outpatient setting with local numbing medicine. Small wounds may be closed with a stitch or two. Related information is available on skin cancers.
In the neck (through a cut in the skin): When a lump or lymph node deep in the neck needs sampling and less invasive methods have not answered the question, a surgeon may make an incision in the skin to reach it. Because of the many important structures in the neck, this is usually done in an operating room. Needle biopsy is often tried first for neck masses, and imaging such as ultrasound or CT scan is often part of the evaluation. See also neck mass (lump, growth).
Anesthesia options
Local anesthesia numbs just the biopsy area with an injected medicine (such as lidocaine, sometimes combined with a medication that reduces bleeding). This is common for skin and many oral biopsies, and the person stays awake.
Local anesthesia with sedation adds medicine to help a person relax while still numbing the area.
General anesthesia puts a person fully asleep and is typically used for throat biopsies and for deeper neck procedures done in the operating room.
The choice depends on the location, the size of the lesion, and individual comfort and health factors. People with an allergy to a numbing medicine can usually be given a safe alternative.
What the procedure involves
Although details vary by site, the general steps are similar:
The area is cleaned, and anesthesia is given so the procedure is not painful.
A small, representative portion of the abnormal tissue is removed with a scalpel, a punch, or a similar instrument, taking care to include enough depth for an accurate diagnosis.
Bleeding is controlled. Depending on the site, the wound may be closed with stitches, sealed (cauterized), or left to heal on its own.
The sample is placed in a preservative solution and sent to the pathology laboratory.
The procedure itself is often brief, though preparation and recovery add time, especially when sedation or general anesthesia is used.
How the tissue is handled and examined
In the pathology laboratory, the sample is preserved, thinly sliced, placed on glass slides, and stained so that its structure shows up under the microscope. A pathologist, a doctor who specializes in diagnosing disease from tissue, examines the architecture and the individual cells to determine whether the tissue is normal, inflamed, benign, precancerous, or cancerous. More detail is available on the page about pathology diagnosis.
When needed, the laboratory can run additional specialized tests on the same tissue, such as stains that highlight specific proteins or tests that look for particular genetic changes. These extra tests can refine the diagnosis and, in some cases, guide treatment choices. A key advantage of an incisional biopsy over cell-only samples is that it preserves the tissue's structure, which many of these analyses require.
Risks and possible complications
Incisional biopsy is generally safe, and serious complications are uncommon. Possible risks include:
Bleeding or bruising at the site.
Infection.
Pain or soreness.
Slow or delayed healing.
A scar.
Occasionally, the sample does not contain enough usable tissue to make a diagnosis, and a repeat biopsy is needed.
Larger, scalpel-based samples and biopsies in certain locations may cause somewhat more discomfort or a larger wound than small punch or needle samples. Deeper procedures in the neck carry the added, though uncommon, risk of injury to nearby structures. Any anesthesia also carries its own small risks. Findings that can signal a problem include worsening pain, increasing redness or swelling, drainage of pus, fever, or bleeding that does not stop with gentle pressure.
What recovery typically looks like
Most people recover quickly. Minor soreness, bruising, or a small amount of bleeding for a day or two is common. Wound-care instructions depend on the site:
Skin wounds are generally kept clean and covered; stitches, if placed, are usually removed within about 1 to 2 weeks.
Mouth and throat sites may be tender for several days; soft foods and avoiding irritation to the area often help.
Neck incisions are cared for as directed by the treating team and may involve activity limits for a short time.
Ordinary activities can often resume soon after, with specific restrictions given based on the procedure. Results usually take several days to a couple of weeks, depending on whether extra laboratory tests are required.
What results can and cannot show
What results can show: An incisional biopsy can usually identify whether tissue is benign, precancerous, or cancerous, and often the specific type of condition. It can frequently show how deep or aggressive an abnormality appears in the sampled piece, which helps guide treatment planning.
What results cannot always show: Because only part of the lesion is removed, the sample may not fully represent the entire abnormality. The most important limitation is "sampling error," the possibility that the small piece taken does not capture the most significant part of the lesion. As a result:
A biopsy can occasionally underestimate (or, less often, overestimate) the severity of a condition compared with what is found when the whole lesion is later removed and examined.
A biopsy showing benign tissue does not always guarantee the entire lesion is benign.
An incisional biopsy does not show whether an abnormality has been completely removed, since removal is not its purpose.
For these reasons, biopsy results are interpreted together with the clinical exam, imaging, and, when needed, additional or repeat sampling. Taking a larger sample, sampling more than one spot, and close communication between the treating clinician and the pathologist all improve accuracy. Questions about results are addressed by the treating clinician, who can explain what the findings mean for an individual situation.