A benign growth is a non-cancerous collection of abnormal cells that grow in a contained way, unlike malignant (cancerous) tumors which invade surrounding tissues and can spread. The appearance of a benign growth varies widely depending on its type and location, whether on the skin, under the skin, or on an internal organ. While many are harmless, knowing the general characteristics can help you identify a normal growth and recognize when a professional evaluation is needed. The key is to look for stability and symmetry, as rapid change and irregularity are often more concerning signs.
General Characteristics of Benign Growths
While every benign growth is different, most share common features that distinguish them from cancerous ones. These traits are related to their slow, contained growth pattern.
- Slow growth: Benign growths typically grow very slowly over months or years, or they remain the same size indefinitely. A sudden or rapid increase in size is a red flag that should be evaluated by a healthcare provider.
- Symmetry and uniform borders: Many benign skin growths, such as common moles, are symmetrical in shape and have smooth, even borders. This is in contrast to many malignant growths, which are often asymmetrical with irregular, jagged edges.
- Uniform color: A benign lesion typically has a consistent color throughout. While the color itself can vary (from pink to brown or black), it does not display multiple, inconsistent shades within the same spot.
- Mobility (for subcutaneous lumps): Lumps found just under the skin, like lipomas, often feel soft, rubbery, and can be moved easily with your fingers. A hard, fixed lump may be more concerning.
- Absence of bleeding or ulceration: Benign growths generally do not spontaneously bleed or form open sores. Bleeding can occur from injury, but persistent bleeding or oozing is a sign that requires medical attention.
Common Types of Benign Skin Growths
Numerous harmless skin growths can appear on the body. Some of the most common types and their typical appearances are outlined below.
Moles (Nevi)
Moles are small skin marks caused by pigment-producing cells. They can be flat or raised, smooth or rough, and range in color from skin-toned to dark brown or black. A common, benign mole is typically symmetrical, has even borders, and a uniform color. Atypical or dysplastic moles are larger and may have a slightly more irregular appearance, but are not cancerous themselves. However, any mole that changes in size, shape, or color should be evaluated for potential melanoma.
Skin Tags (Acrochordons)
These are soft, flesh-colored, or brownish growths that often look like a small piece of skin hanging from a tiny stalk. They commonly appear in areas of friction, such as the neck, armpits, and groin. Skin tags are completely harmless, though they can become irritated by clothing or jewelry.
Lipomas
As one of the most common types of benign tumors, a lipoma is a soft, round, or oval-shaped lump of fatty tissue that grows slowly under the skin. They feel soft and doughy to the touch and can be easily moved under the skin with your fingers. Lipomas are most frequently found on the back, shoulders, neck, and arms.
Seborrheic Keratoses
More common in middle-aged and older individuals, seborrheic keratoses are wart-like spots that appear to be "stuck on" the skin. They can be light tan, brown, or black, and have a waxy, scaly, or rough surface. While they can be itchy or get irritated, they are harmless and are not related to sun exposure.
Dermatofibromas
A dermatofibroma is a small, firm, reddish-brown bump caused by an accumulation of soft tissue cells. They often appear on the legs and may itch. A tell-tale sign is the "dimple sign," where the lesion dimples inward when you pinch the skin around it.
Benign vs. Malignant: A Comparison
| Feature | Benign Growth | Malignant (Cancerous) Growth |
|---|---|---|
| Growth Rate | Typically slow-growing or stable over time. | Often grows rapidly and uncontrollably. |
| Borders | Usually have smooth, even, and well-defined borders. | Tend to have irregular, jagged, or poorly defined borders. |
| Color | Generally uniform in color throughout the growth. | May have varied shades or colors, including brown, black, and red. |
| Size | Often smaller than 6mm in diameter, though larger types exist like lipomas. | Can be larger than 6mm in diameter, but size alone is not a diagnostic factor. |
| Mobility | Subcutaneous lumps (like lipomas) are often soft and moveable. | Often feels hard and fixed in place under the skin. |
| Symptom Profile | Usually asymptomatic unless pressing on a nerve or becoming irritated. May cause mild itching. | May cause symptoms like bleeding, oozing, itching, or pain. |
| Spread | Does not spread to other parts of the body. | Can invade nearby tissue and metastasize (spread) to distant areas. |
When to Seek Medical Advice
It is important to remember that some benign growths can mimic cancerous ones, and only a medical professional can provide a definitive diagnosis. You should consult a dermatologist or other healthcare provider if you notice any changes in an existing growth or discover a new one, particularly if it displays the following characteristics:
- Changes in size, shape, or color: Any evolution in appearance should be promptly evaluated.
- Irregularity: Look for asymmetry, uneven borders, or inconsistent colors within the growth.
- Bleeding, itching, or oozing: These can be signs of irritation or a more serious issue.
- Rapid growth: A growth that appears suddenly and grows quickly needs attention.
- Persistent sores: Any non-healing sore or ulceration warrants a medical check.
Conclusion
While discovering a new lump or bump on your body can be alarming, a vast majority of such growths are benign and harmless. Learning to recognize the general characteristics of a benign growth, such as its slow and stable growth, uniform appearance, and clear borders, is the best way to feel confident about your health. However, because some benign growths can eventually develop cancerous potential, or their appearance may overlap with that of a malignant lesion, it is always wise to seek a professional medical opinion on any new or changing skin abnormality. Regular self-examinations of your skin and body are a crucial part of early detection and overall health awareness.
For more in-depth information about skin growths and conditions, you can consult reputable sources like the Cleveland Clinic.
Frequently Asked Questions
Are all benign growths soft and moveable?
No, not all benign growths are soft and moveable. While a lipoma is a soft, moveable lump of fatty tissue, other benign growths like dermatofibromas are firm bumps under the skin. Cysts can also feel soft or firm depending on their contents.
Can a benign mole turn into skin cancer?
Yes, in rare cases, a benign mole can become cancerous, specifically melanoma. This is why it is important to monitor moles for any changes in symmetry, border, color, or diameter.
Do benign growths always have symptoms?
Not always. Many benign growths are completely asymptomatic. However, some can cause symptoms if they are large enough to press on nerves or organs, or if they become irritated. Symptoms can include pain, itching, or pressure.
What is a hemangioma and is it dangerous?
A hemangioma is a common benign tumor formed by an overgrowth of blood vessels. They often appear as red or purple bumps on the skin and are generally harmless. Some are present at birth and may disappear over time.
How can I tell if a lump is a benign cyst or something else?
A cyst is a sac filled with fluid or other substances, while a benign tumor is a solid mass of cells. Your doctor can determine the nature of a lump through a physical exam, and sometimes an ultrasound or biopsy, to distinguish it from a tumor or other issue.
Should I worry about a skin tag?
Skin tags are harmless benign growths and typically do not require treatment unless they become irritated by clothing or if you want them removed for cosmetic reasons. There is no medical reason to be concerned about them.
Does size matter when it comes to benign growths?
Size can be a factor, but it is not definitive on its own. While many malignant lesions are larger than 6mm, some can be smaller, and some benign growths can be quite large. The most important factor is a change in the growth's characteristics.
