How would you define a sebaceous cyst?

A sebaceous cyst is accurately defined as a closed sac filled with sebum and debris. These cysts, also referred to as epidermoid cysts, develop when the sebaceous gland, which is responsible for producing oil (sebum) that lubricates the skin and hair, becomes blocked. This blockage leads to the accumulation of sebum, dead skin cells, and other debris, forming a sac-like structure beneath the skin.

This definition highlights the cyst's nature as a benign, often painless growth under the skin's surface, distinguishing it from other skin conditions. In contrast, the other choices describe different skin issues or conditions: a viral infection would not relate to the characteristics of a sebaceous cyst; an open wound does not encapsulate a sac filled with material; and while acne lesions can occur in relation to sebaceous glands, they are distinct from sebaceous cysts, both in formation and appearance.