What is a sebaceous cyst that usually occurs on the scalp, neck, or back called?

A sebaceous cyst, typically found on the scalp, neck, or back, is referred to as a steatoma. This type of cyst is formed from sebaceous glands that become blocked and is filled with sebum, the oily substance that the glands produce. Steatomas are generally benign and can vary in size. They are commonly associated with hair follicles and can appear anywhere on the body where such follicles are present, although they are most frequently encountered in the areas mentioned.

In contrast, a papule is a small, raised, solid pimple or swelling that is often a sign of an inflammatory response; it does not refer specifically to the cyst formation seen in steatomas. A veruca, or wart, is caused by a viral infection and presents differently on the skin. Eczema, on the other hand, is a chronic inflammatory skin condition characterized by red, itchy patches rather than the cystic formations of a steatoma. Thus, understanding the characteristics and differences between these terms clarifies why steatoma is the correct answer regarding sebaceous cysts.