Determining Whether Skin Lumps Are Benign or Potentially Cancerous

May 7th 2016

Size and Shape

Doctors advise patients to consider many factors in assessing the potential risk of an unexplained skin growth. Using the mnemonic "ABCD," it is possible to evaluate lumps, bumps and irregular patches of skin for signs of cancer. "A" stands for "asymmetry," and refers to the tendency for cancerous growths to have irregular distributions of mass. "B" refers to the borders of the lesions, which are often jagged.


"C" is for "color," since many melanomas begin as brown or black spots on the skin. Carcinomas are also typically darker than the surrounding skin. Cancerous growths, unlike normal moles, often change color on short timescales. They can also change size, which is why dermatologists advise keeping track of the lump's diameter, or "D."

Changes Over Time

The "ABCD" mnemonic works well for most types of cancer, but aggressive melanomas sometimes grow vertically, rather than horizontally, and can become very dangerous if not detected early. To catch granular melanomas, add "EFG" to the self-examination. "E" stands for "evolving," as granular melanomas can change rapidly. "F" stands for "firm," since granular tumors are tough and rough to the touch. "G" is for "growing [vertically]," and is a reminder that not all skin cancers present the common sprawling growth pattern.

Benign Growths

If you find a growth, lump or other irregularity somewhere on your skin, remember it does not necessarily mean you have cancer. Many harmless conditions cause lumps to appear on or under the skin without other symptoms. Lipomas, for example, are benign deposits of fat that grow under the skin, usually in middle age. Warts, moles and skin tags are equally harmless, though they can grow suddenly in unexpected places, causing alarm.


Unexplained lumps in the skin are usually benign, but they may be the first sign of a potentially life-threatening cancer. Knowing the difference between them, and acting on your suspicions as early as possible, can mean the difference between a healthy life and a difficult struggle with cancer. Though there is no universal sign a lump or lesion is cancerous, many types of skin cancer have certain features in common. Ultimately, cancer can only be diagnosed by a doctor. If you are in any doubt about the nature of a skin lump, do not hesitate to consult with your dermatologist.

More in category

Related Content