A noticeable bump or swelling on the head, commonly referred to as a scalp lump, can be a source of concern. These lumps are common and can arise from various causes, including benign skin growths, inflammatory conditions, or, in rare instances, more serious issues. This article provides general information about different types of scalp lumps and offers guidance on when professional medical evaluation may be necessary. This information is not a substitute for advice from a healthcare professional.
Common Benign Scalp Lumps
Many scalp lumps are non-cancerous and generally harmless. Pilar cysts (trichilemmal cysts) are common, benign cysts originating from hair follicles on the scalp. Pilar cysts often feel like smooth, flesh-colored, firm, and mobile lumps under the skin. They are filled with keratin, a protein found in hair, skin, and nails. These cysts typically grow slowly and are usually painless unless they rupture or become irritated.
Lipomas are another common type of benign scalp lump. These soft, movable, fatty tumors grow slowly in the layer of fat cells beneath the skin. They are generally painless and feel doughy to the touch.
Sebaceous cysts, often called epidermal or epidermoid cysts, form when sebaceous glands, which produce oil for skin and hair, become blocked. These slow-growing lumps can appear on the scalp, are usually skin-colored or yellowish, and may contain a cheesy, keratinous material.
Osteomas are benign growths of bone tissue. These hard, immobile lumps form slowly over time. While less common than cysts or lipomas, they are another non-cancerous type of scalp lump.
Inflammatory and Infection-Related Lumps
Scalp lumps can also result from inflammation, infection, or injury. Folliculitis, boils, and abscesses are examples caused by infections of hair follicles or deeper skin tissues. Folliculitis involves inflamed hair follicles, appearing as small, red, or pus-filled bumps. Boils (furuncles) are deeper hair follicle infections that can be painful, red, warm, and contain pus. Carbuncles are clusters of boils forming a connected area of infection under the skin.
Insect bites or stings can cause temporary, localized swelling and lumps on the scalp. These lumps may be painful, itchy, and red. Scratching can lead to infection, increasing pain, redness, and pus.
A blow to the head can result in a hematoma, a collection of blood under the skin. Often called “goose eggs,” these typically resolve as the blood is reabsorbed. While often minor, larger or persistent hematomas, especially after significant head trauma, warrant medical evaluation.
When a Lump Might Be Concerning
While many scalp lumps are benign, certain characteristics warrant medical evaluation to rule out more serious conditions. A lump that rapidly increases in size or changes color or shape warrants professional attention. New or worsening pain or tenderness is also a sign to watch for.
Bleeding from the lump or discharge, such as pus, indicates a potential issue like infection or irritation. Lumps that feel hard and are immobile, or those that are new and unexplained, should also be evaluated. Any lump causing discomfort or persistent concern should be checked for proper diagnosis.
Diagnosis and Next Steps
A medical evaluation for a scalp lump typically begins with a physical examination of the lump and surrounding area and a review of your medical history, including when the lump appeared, its symptoms, and any changes. This initial assessment helps understand the lump’s nature.
If further investigation is needed, diagnostic tools like ultrasound, MRI, or CT scans can provide detailed views of the lump’s size, depth, and composition. A biopsy, involving a small tissue sample for laboratory analysis, may also be performed to determine its exact nature. Treatment depends on the diagnosis, ranging from observation for benign lumps to surgical removal. Seek professional diagnosis and avoid self-treatment, such as attempting to pop or remove a lump at home, as this can lead to complications like infection.