Skin cancer check: what to expect
Skin biopsy results: what the pathology report means
After a skin biopsy, the tissue is examined under a microscope, and results most often come back in a few days to a week or more. (MedlinePlus, 2025) This page explains the common findings in plain words. How the biopsy itself is done is on skin cancer check: what to expect.
Who reads the sample and what the report contains
All skin biopsy samples go to a lab, where a pathologist looks at them under a microscope and might do other tests. Often they go to a dermatopathologist, a doctor with special training in skin biopsy samples. (ACS, 2026) If the doctor cannot tell for sure whether melanoma cells are in the sample just by looking, extra lab tests are done on the cells. (ACS, 2026)
A pathology report usually has a gross description (what the sample looked like, its size and color), a microscopic description, and a final diagnosis. The microscopic part can note tumor margins, meaning whether cancer cells are present at the edges of the sample. (ACS, 2026)
Common results, in plain words
| Result | What the sources say |
|---|---|
| Benign (not cancer) | You may not need any further treatment. A biopsy can also find other skin problems, such as psoriasis, dermatitis, or an infection from bacteria or fungus. (MedlinePlus, 2025) |
| Common mole | Common moles are not cancerous. Very few turn into melanoma. (NCI, 2022) |
| Seborrheic keratosis | A benign skin growth that commonly appears after age 40 and can look like a skin cancer; a biopsy may be needed to confirm it. (MedlinePlus, 2024) |
| Actinic keratosis | A precancerous skin lesion caused by sun exposure. A small number become squamous cell skin cancer. (MedlinePlus, 2024) (MedlinePlus, 2025) |
| Dysplastic nevus (atypical mole) | A mole that looks different from a common mole. Only rarely does one turn into melanoma, but having them raises the risk of melanoma, and the risk rises with the number. (NCI, 2022) |
| Basal cell carcinoma (BCC) | The most common type of skin cancer, about 8 out of 10 skin cancers. It tends to grow slowly and rarely spreads to other parts of the body. (ACS, 2026) (MedlinePlus, 2025) |
| Squamous cell carcinoma in situ (Bowen disease) | The earliest form of squamous cell cancer. It does not spread to nearby tissues, because it is still in the outermost layer of the skin. (MedlinePlus, 2025) |
| Squamous cell carcinoma (SCC) | A skin cancer of the top layer of skin. There is a risk that it may spread to other parts of the body. (MedlinePlus, 2025) |
| Melanoma in situ (stage 0) | The cancer is only in the epidermis, the outermost skin layer, and has not grown any deeper. (ACS, 2026) |
| Invasive melanoma | A cancer of melanocytes, the cells that make skin pigment. It can invade nearby tissues and spread to other parts of the body. The report then notes features such as thickness and ulceration (below). (NCI, 2022) (ACS, 2026) |
What a melanoma report describes, in general terms
If melanoma is found, the pathologist looks at important features such as the tumor thickness and mitotic rate (the share of cells that are actively dividing). These features help set the stage and may help show how likely it is to spread. (ACS, 2026)
- Thickness (Breslow measurement): melanomas less than 1 millimeter thick have a very small chance of spreading; as a melanoma becomes thicker, the chance rises. (ACS, 2026)
- Ulceration: a sore over the melanoma. Ulcerated melanomas tend to have a worse outlook. (ACS, 2026)
- Stage: the earliest melanomas are stage 0 (melanoma in situ), and stages then range from I through IV. Ask your doctor to explain your stage in a way you understand. (ACS, 2026)
If a shave biopsy of a suspected melanoma is not deep enough, the sample might not be thick enough to measure how deeply the cancer has grown. (ACS, 2026)
Why more removal or a second opinion may come up
- The whole spot was not removed: if a benign lesion was only partly removed at biopsy, you and your provider may decide to remove it completely. (MedlinePlus, 2025)
- Second opinion: if you or your care team have concerns about the diagnosis, a consulting pathologist can review your samples. (ACS, 2026) Pathologists may also ask an expert before giving a result, which can add a few days. (ACS, 2026)
- Inconclusive result: the biopsy might need to be repeated, or other tests might be needed. (ACS, 2026)
Your doctor decides what your result means for you. This page does not give treatment advice. If you have an abnormal result, see after an abnormal screening result for questions to ask.
After the biopsy: when to call
The biopsy area may be tender for a few days, and you may have a small amount of bleeding. MedlinePlus says: (MedlinePlus, 2025)
If you have moderate bleeding, apply pressure to the area for 10 minutes or so. If the bleeding does not stop, call your provider right away. You should also call your provider if you have signs of infection, such as:
- More redness, swelling, or pain
- Drainage coming from or around the incision that is thick, tan, green, or yellow, or smells bad (pus)
- Fever
New or changing spots: when MedlinePlus says to contact your provider
Each MedlinePlus article on these conditions has its own list, quoted here in full.
Basal cell skin cancer: (MedlinePlus, 2025)
Contact your provider for an appointment if you have a sore or spot on your skin that changes in:
- Appearance
- Color
- Size
- Texture
Also contact your provider if a spot becomes painful or swollen, or if it starts to bleed or itch.
Squamous cell skin cancer: (MedlinePlus, 2025)
Contact your provider for an appointment if you have a sore or spot on your skin that changes in:
- Appearance
- Color
- Size
- Texture
Also contact your provider if a spot becomes painful or swollen or if it starts to bleed or itch.
Melanoma: (MedlinePlus, 2026)
Contact your provider if you notice a new growth or any other changes in your skin. Also talk to your provider if an existing spot:
- Changes in shape, size or color
- Becomes painful, swollen, or inflamed
- Starts to bleed or itch
Actinic keratosis: (MedlinePlus, 2024)
Contact your provider if you see or feel a rough or scaly spot on your skin, or if you notice any other skin changes.
Seborrheic keratosis: (MedlinePlus, 2024)
Contact your provider if you have symptoms of seborrheic keratosis.
Also contact if you have new symptoms, such as:
- A change in the appearance of the skin growth
- New growths
- A growth that looks like seborrheic keratosis, but occurs by itself or has ragged borders and irregular color. Your provider will need to examine it for skin cancer.
Where they differ:
- How long results take: MedlinePlus says a few days to a week or more; the ACS says some routine biopsy results might be ready in a day or two, with extra processing or a second opinion adding a few days. (MedlinePlus, 2025) (ACS, 2026)
- How deep melanoma matters: the ACS describes melanomas under 1 millimeter as having a very small chance of spreading; MedlinePlus says one deeper than 4 millimeters is more likely to have spread. (ACS, 2026) (MedlinePlus, 2026)
- How often basal cell cancer spreads: the ACS calls spread to other parts of the body rare; MedlinePlus says it almost never spreads beyond the original location, though untreated it may grow into nearby tissue and bone. (ACS, 2026) (MedlinePlus, 2025)
Questions people ask
How long do skin biopsy results take?
MedlinePlus says results most often come back in a few days to a week or more. The ACS says extra processing, extra tissue sections or a second opinion can add a few days. (MedlinePlus, 2025) (ACS, 2026)
Who reads a skin biopsy?
A pathologist looks at the sample under a microscope. Skin samples are often sent to a dermatopathologist, a doctor with special training in skin biopsy samples. (ACS, 2026) (ACS, 2026)
What does it mean if my report says the margins are involved?
Margins describe whether cancer cells are present at the edges of the sample. If the whole spot was not removed at the biopsy, you and your provider may decide to remove it completely. (ACS, 2026) (MedlinePlus, 2025)
Should an atypical mole be removed?
The NCI says people normally do not need a dysplastic nevus or common mole removed to prevent melanoma; doctors usually remove only moles that have changed or new suspicious spots. (NCI, 2022)
What is Breslow thickness?
It is the measurement of how thick a melanoma is. The ACS says melanomas less than 1 millimeter thick have a very small chance of spreading, and the chance rises as the melanoma becomes thicker. (ACS, 2026)
Can I get a second opinion on my biopsy?
Yes. If you or your care team have concerns about the diagnosis, your samples can be reviewed by a consulting pathologist for a second opinion. (ACS, 2026)
What if the result is inconclusive?
The pathologist could not give a diagnosis from the tests done. The biopsy might need to be repeated, or other tests might be needed; ask your care team about next steps. (ACS, 2026)