SymptomSkin, hair & nails
Skin Growths: Common Types and Warning Signs
A skin growth is any new bump, spot or raised patch on or under the skin. Most are harmless: moles, skin tags, seborrheic keratoses, cherry angiomas, cysts and lipomas. A smaller number are precancerous, such as actinic keratoses, or are skin cancers, such as basal cell carcinoma, squamous cell carcinoma and melanoma. A growth that is changing, bleeding, not healing or looks different from your other spots should be checked by a doctor.
Also called: Skin lesion, cutaneous growth, skin tumor, skin lump, new spot on skin
At a glance
- What it is
- A new bump, spot, patch or lump on the skin.
- Most common types
- Moles, skin tags, seborrheic keratoses, cherry angiomas, epidermoid cysts, warts and lipomas.
- Concerning types
- Actinic keratosis (precancer), basal cell carcinoma, squamous cell carcinoma, melanoma.
- Key warning signs
- Change in size, shape or color, bleeding, crusting or a sore that does not heal in 4 weeks.
- Diagnosis
- Visual exam with a dermatoscope, and a biopsy if there is doubt.
- Treatment
- Often none. Removal by freezing, shaving, scraping or excision when needed.
When to get help
See a doctor within a day or two
- A dark or multicolored spot that is quickly getting bigger, changing shape or bleeding
- A firm, red, fast-growing lump that has appeared over a few weeks, especially on sun-exposed skin
- A growth with redness spreading around it, heat, pus and fever (possible infected cyst or abscess)
Book a routine appointment
- A mole that looks different from your other moles (the "ugly duckling" sign)
- A sore, scab or pearly bump that bleeds, crusts and does not heal within 4 weeks
- A rough, scaly patch on the face, ears, scalp or hands that keeps coming back
- A lump under the skin larger than 5 cm (2 in), hard, fixed or growing
- Many new seborrheic keratoses appearing suddenly
Usually safe to manage at home
- A soft, flesh-colored skin tag in a skin fold that does not bother you
- A stable, brown, "stuck-on" waxy spot that has looked the same for months
- Small bright red dots (cherry angiomas) in an adult
What counts as a skin growth
Doctors call any visible spot on the skin a lesion. A growth is a lesion that is raised or that makes new tissue, as opposed to a flat rash or a discoloration. Growths can arise from:
- pigment cells (melanocytes): moles, freckles, melanoma
- surface skin cells (keratinocytes): seborrheic keratoses, actinic keratoses, warts, basal and squamous cell cancers
- blood vessels: cherry angiomas, hemangiomas, pyogenic granulomas
- structures under the skin: cysts, fat (lipomas), fibrous tissue (dermatofibromas)
Most people develop more skin growths with age and sun exposure. By middle age almost everyone has several.
Types of skin growths: names and how to recognize them
Common harmless growths
| Growth | What it looks like | Who gets it |
|---|---|---|
| Mole (nevus) | Round, even brown or skin-colored spot, flat or raised, under 6 mm | Everyone. Most appear before age 30 |
| Seborrheic keratosis | Waxy, "stuck-on" brown to black bump with a warty or crumbly surface | Adults over 40. Very common |
| Skin tag | Soft, flesh-colored flap on a thin stalk | Neck, armpits, groin, eyelids. More common with weight gain and diabetes |
| Cherry angioma | Bright red, dome-shaped dot, 1 to 5 mm | Adults over 30 |
| Epidermoid (sebaceous) cyst | Round lump under the skin, often with a central pore, may leak cheesy material | Face, neck, back, chest |
| Lipoma | Soft, doughy, painless lump that moves under the skin | Trunk, shoulders, arms |
| Dermatofibroma | Firm, brownish bump that dimples inward when you pinch it | Legs, often after an insect bite |
| Wart | Rough, raised, cauliflower-like surface with tiny black dots | Hands, feet, knees. Caused by HPV |
| Sebaceous hyperplasia | Small yellowish bumps with a central dip | Forehead and nose in middle age |
| Milia | Tiny hard white bumps | Around the eyes and cheeks |
Seborrheic keratoses cause the most worry because they can be large and dark. They are not related to sun damage and never turn into cancer, but a dark one can resemble melanoma, so a doctor should look at any that are changing or that you are unsure about.
Precancerous growths
An actinic keratosis is a rough, scaly, sandpaper-like patch on skin that has had years of sun: the face, ears, bald scalp, forearms and backs of the hands. It is often easier to feel than to see. A small proportion turn into squamous cell carcinoma, so they are usually treated. Searches for a "rough, misshapen skin growth" often describe these, or a seborrheic keratosis.
Skin cancers
| Cancer | Typical appearance | Behavior |
|---|---|---|
| Basal cell carcinoma | Pearly or shiny bump with tiny blood vessels, or a sore that bleeds, scabs and never fully heals | Most common skin cancer. Grows slowly and rarely spreads, but damages tissue locally |
| Squamous cell carcinoma | Firm red bump, scaly crusted patch, or a sore that does not heal, on sun-exposed skin | Can spread if left, especially on the lip and ear and in people with weak immune systems |
| Melanoma | New or changing mole: uneven shape, several colors, larger than 6 mm, growing | Less common but most dangerous. Can spread early |
| Keratoacanthoma | Dome-shaped bump with a central crater, grows over weeks | Usually treated like squamous cell carcinoma |
| Merkel cell carcinoma | Painless, firm, red to purple lump that grows fast | Rare but aggressive, mainly in older or immunosuppressed adults |
Read more about basal cell carcinoma, squamous cell carcinoma and melanoma.
Aggressive skin growths
Growths that are described as aggressive are those that grow quickly or spread: nodular melanoma (a dark or red, firm lump that grows over weeks), Merkel cell carcinoma, some squamous cell carcinomas and, rarely, sarcomas under the skin. The shared warning feature is speed. A lump that has clearly grown over a few weeks needs to be seen soon, not at a routine appointment months away.
The ABCDE check for moles and dark spots
Use these signs to decide whether a pigmented growth needs checking:
- A, asymmetry: one half does not match the other.
- B, border: ragged, notched or blurred edges.
- C, color: several shades of brown, black, red, white or blue.
- D, diameter: larger than about 6 mm (a pencil eraser), though melanomas can be smaller.
- E, evolving: any change in size, shape, color, height, or new itching or bleeding.
Also look for the ugly duckling: a spot that looks different from all your other moles. See skin moles for more detail.
What causes skin growths
- Sun exposure: ultraviolet light drives actinic keratoses, basal and squamous cell carcinomas, melanoma and age spots.
- Age: seborrheic keratoses, cherry angiomas and skin tags all increase after 40.
- Genetics: a family tendency to many moles, seborrheic keratoses or skin cancer.
- Viruses: HPV causes warts; a poxvirus causes molluscum contagiosum.
- Friction and weight: skin tags form where skin rubs.
- Hormones: pregnancy can bring new skin tags and darken moles.
- Blocked follicles or trapped skin: epidermoid cysts and milia.
- Weak immune system: organ transplant recipients have a much higher risk of squamous cell carcinoma.
When to see a doctor about a new skin growth
See a primary care doctor or dermatologist if a growth:
- is new and you are over 40, particularly on sun-damaged skin
- changes in size, shape, color or texture
- bleeds without being injured, crusts or forms a sore that does not heal within 4 weeks
- itches or hurts persistently
- is a lump that is hard, fixed or growing
- looks unlike your other spots
People with a personal or family history of skin cancer, many moles (more than 50), very fair skin that burns easily, or a weakened immune system should have regular skin checks.
How doctors diagnose skin growths
A doctor looks at the growth closely, often with a dermatoscope, a magnifier with built-in light that shows patterns beneath the surface. Many growths, such as seborrheic keratoses and cherry angiomas, can be diagnosed on sight.
If there is any doubt, a skin biopsy is taken under local anesthetic:
- Shave biopsy: the top layers are shaved off.
- Punch biopsy: a small cylinder of skin is removed with a tool like a tiny cookie cutter.
- Excisional biopsy: the whole growth is cut out with a margin. This is preferred for a suspected melanoma.
Lumps under the skin may be checked with an ultrasound first.
Treatment for skin growths
Harmless growths only need treatment if they are irritated, catch on clothing, or bother you cosmetically. Insurance often does not cover purely cosmetic removal.
- Cryotherapy: freezing with liquid nitrogen for seborrheic keratoses, actinic keratoses, warts and skin tags.
- Shave removal or snipping: for skin tags and raised moles.
- Curettage and electrodesiccation: scraping and cauterizing, used for some seborrheic keratoses and small basal cell carcinomas.
- Excision: cutting out the growth with stitches, for cysts, lipomas, suspicious moles and many skin cancers.
- Mohs surgery: layer-by-layer removal for skin cancers on the face and other areas where saving tissue matters.
- Creams and light therapy: 5-fluorouracil, imiquimod or photodynamic therapy for actinic keratoses and some superficial skin cancers.
- Laser: for cherry angiomas and some cosmetic lesions.
Do not cut off, burn or tie off growths at home. You may cause infection or scarring, and a skin cancer removed without testing can be missed.
Preventing new skin growths
You cannot prevent seborrheic keratoses or most moles, but you can lower the risk of sun-related growths and skin cancer:
- use broad-spectrum sunscreen of SPF 30 or higher on exposed skin, reapplied every 2 hours outdoors
- wear a wide-brimmed hat and cover up during peak sun, roughly 10 a.m. to 4 p.m.
- never use tanning beds
- check your skin once a month, using a mirror or a partner for your back and scalp
Frequently asked questions
What are the most common types of skin growths?
The most common are moles, seborrheic keratoses, skin tags, cherry angiomas, epidermoid cysts, warts and lipomas. All are benign. The most common precancerous growth is actinic keratosis, and the most common skin cancer is basal cell carcinoma.
How can I tell if a skin growth is cancerous?
You cannot be certain by looking, but warning signs include rapid growth, bleeding without injury, a sore that does not heal within 4 weeks, a pearly or shiny surface, a firm red lump, and in moles the ABCDE features. A doctor may need a biopsy to confirm.
What causes rough skin growths?
Rough growths are usually seborrheic keratoses (waxy and warty, not sun-related), actinic keratoses (scaly patches caused by sun damage) or warts (caused by HPV). Actinic keratoses should be treated because some turn into squamous cell carcinoma.
When should I see a doctor about a new skin growth?
See a doctor if a growth is changing, bleeding, crusting, painful or not healing after 4 weeks, or if it looks different from your other spots. A lump that is growing quickly over weeks should be seen promptly.
Are seborrheic keratoses cancerous?
No. Seborrheic keratoses are benign and do not become cancer. They can look alarming because they may be dark and large, and occasionally a melanoma looks similar, so get any changing or unusual one checked.
Can I remove a skin growth myself?
It is not recommended. Home removal risks bleeding, infection and scarring, and it means the growth is never examined under a microscope. A doctor can remove most growths quickly in the office and send them for testing if needed.
Sources
This guide was written from current patient and clinical guidance, including:
- American Academy of Dermatology: Seborrheic keratoses; Skin cancer types
- American Cancer Society: Skin cancer signs and symptoms
- NHS: Skin cancer (melanoma)
- MedlinePlus: Skin lumps
- Skin Cancer Foundation: Skin cancer information