Physical Characteristics of Epidermoid Cysts
Epidermoid cysts typically present as firm, skin-colored nodules that feel solid to palpation, not hard like bone or cartilage. 1, 2
Tactile Characteristics
Epidermoid cysts are described as "firm" rather than hard, distinguishing them from truly hard lesions like bone or calcified structures 1, 3
A distinct capsule or wall structure can often be felt beneath the skin, which contributes to the firm consistency 4
The cysts are generally well-defined with a palpable border, making them easy to distinguish from surrounding tissue 5
When large, they may feel soft and tumorlike rather than firm, as the cystic expansion can create a more fluctuant quality in giant variants 5
Clinical Presentation Features
An epidermal punctum (a visible dark central opening on the surface) is the clinical diagnostic hallmark when present 1, 4
The lesions are typically painless unless inflamed or infected, at which point they become tender and may feel warmer 4, 2
Patients often report a longstanding painless nodule that has been present for months to years before seeking medical attention 4
The cysts contain thick white-yellow keratinous debris (described as "cheesy" material) rather than liquid, which contributes to their firm consistency 4
Important Clinical Distinctions
Epidermoid cysts feel firmer and more solid than simple abscesses, which are uniformly fluctuant and contain liquid pus 4
The well-defined capsule makes dissection extremely easy during excision, as the mass separates cleanly from surrounding tissue 5
Inflammation changes the texture: when an epidermoid cyst becomes inflamed, it may feel softer and more fluctuant due to rupture of the cyst wall and inflammatory response 6, 4