The term “wen” is an informal, sometimes archaic, word used to describe various common, usually benign lumps that form just beneath the skin’s surface. These growths are typically slow-growing and painless. Modern medical terminology classifies these lumps based on their cellular composition and origin. The two most frequent conditions referred to as a “wen” are cysts and lipomas, which are distinct in their makeup.
The Medical Conditions Colloquially Known as a Wen
The most common lumps called a wen are epidermoid or pilar cysts, which are sacs filled with keratin, the protein that makes up hair and the outer layer of skin. These cysts form when skin cells become trapped beneath the surface and continue to shed, accumulating inside a closed sac. Although historically mislabeled as “sebaceous cysts,” this term is inaccurate because the growths do not originate from the oil-producing sebaceous glands. The contents of these cysts are thick and cheese-like, consisting entirely of keratin.
The second type of lump identified as a wen is a lipoma, which is fundamentally different because it is a soft, non-cancerous tumor composed of mature fat cells. Lipomas are classified as benign soft tissue tumors, meaning they are encapsulated and do not spread. Unlike cysts, which contain keratin debris, lipomas are an overgrowth of fatty tissue clumped together just under the skin. They are typically slow-growing.
How These Lumps Form and Appear
Epidermoid cysts often form when surface skin cells are introduced into the deeper layer of the skin, perhaps due to trauma or a clogged pore, and begin to multiply. Pilar cysts, a type of epidermoid cyst, originate from the cells of the hair follicle root sheath and are most commonly found on the scalp. The continuous production of keratin within the sac causes the lump to slowly expand.
Cysts are often firm and dome-shaped, sometimes featuring a tiny dark plug on the surface. Lipomas, by contrast, are generally much softer, feeling doughy or rubbery to the touch. A defining characteristic of a lipoma is its mobility; it tends to move easily when pressed with a finger because it is loosely situated within the subcutaneous fat layer. Both lumps are frequently found on the back, neck, and shoulders, though pilar cysts primarily occur on the scalp.
Diagnosis, Monitoring, and Removal
Any new or unexplained lump beneath the skin warrants professional medical evaluation to confirm its benign nature and rule out more serious conditions. Diagnosis is often made by a healthcare provider through a physical examination based on the lump’s appearance and feel. Immediate medical attention should be sought if a lump exhibits sudden, rapid growth, becomes painful, or shows signs of infection such as redness, warmth, or feels hard and fixed in place.
Treatment for confirmed benign lumps is usually elective, driven by cosmetic concerns or discomfort caused by the lump’s size or location. The standard and most definitive treatment for both cysts and lipomas is surgical excision, performed as an outpatient procedure under local anesthetic. For cysts, the entire sac wall must be removed to prevent recurrence. Lipomas are typically removed through a small incision, where the fatty mass is separated from surrounding tissue.