Types of Skin Lumps 

Skin lumps can come in many different shapes and sizes. These can be divided into 3 main categories based on the type of tissue in which they occur. These categories include cysts, benign tumors (non-cancerous), and malignant tumors (cancerous).

Common non-cancerous skin lumps include cysts, lipomas, sebaceous hyperplasia (clogged oil glands), warts, and moles.

Cysts are noncancerous sacs filled with fluid or semisolid material and can appear anywhere on the body. They can vary in size from tiny bumps to large cyst-like growths.

Sebaceous cysts are a common type of cyst that forms due to blocked sebaceous glands in the skin. These slow-growing lumps typically don’t require treatment unless they become infected or inflamed.

Lipomas (link to All About Lipomas and Moles article) are usually soft and movable lumps beneath the skin caused by an overgrowth of fat cells. They tend to appear as soft yellowish bumps and occur in middle-aged adults.

These generally don’t cause any symptoms other than the visible lump itself. However, they may need to be removed if they become painful or interfere with movement.

Hernias also appear as lumps under the skin, but these occur when fat or organs push through weak spots in the abdominal muscles.

Warts are small bumps caused by a virus that invades the top layer of the skin called human papillomavirus (HPV). They are contagious and often spread from person to person through direct contact or sharing items such as towels or razors. Warts can range in size from very small to large growths covering a larger area of skin.

Moles are dark spots on your skin that vary in size, shape, color, and texture depending on where they appear on your body. Many moles are harmless but some may require medical attention if they change in color or shape suddenly or become itchy or painful.

Tumors may appear as hard lumps under the skin due to the rapid growth of cells caused by cancerous cells in the affected area. Some can be benign tumors (noncancerous), while others may be malignant (cancerous). 

It is important to contact your doctor immediately if you notice any changes in existing moles or see any new lumps that look suspiciously like tumors so that they can be properly diagnosed and treated accordingly.

Malignant tumors are made up of cancerous cells that grow quickly and have the potential to spread to other parts of the body if left untreated.

Cancerous skin lumps, such as basal cell carcinoma or squamous cell carcinoma, are typically firm and red with irregular borders. It’s important to note that some cancers may initially appear as benign lumps so it’s always best to get them examined by a professional.

Causes of Skin Lumps 

The cause of skin lumps depends on the type and location of the lump present. In many cases, there is no known cause—lumps can simply develop without warning.

The most common cause of benign skin lumps is an infection or inflammation. This can occur when bacteria or viruses enter the body through a cut or sore on the skin.

Other causes include injuries, allergic reactions, clogged sweat glands, hormone imbalances, abnormal growths due to sun damage, and genetics.

The cause of cancerous skin lumps can vary from person to person but generally occurs when DNA mutations allow cells to multiply uncontrollably and form tumors.