What type of cyst is associated with lesions on the external angle of the eye, including hair follicles?

The type of cyst associated with lesions on the external angle of the eye, including hair follicles, is a dermoid cyst. Dermoid cysts are benign tumors that can contain skin components, hair follicles, and even sebaceous glands. They often appear as firm, round lesions and are typically found in the periorbital region, particularly near the eyebrow or at the lateral canthus of the eye, which corresponds to the external angle location mentioned in the question.

These cysts arise from embryonic tissue and can occur in various locations throughout the body, but when they develop in proximity to the eye, they are often recognized by their characteristic appearance and association with hair follicles. The benign nature of dermoid cysts usually means they do not typically cause symptoms unless they are large enough to exert pressure or lead to cosmetic concerns, prompting surgical removal if necessary.

Other options like chalazion, pterygium, and conjunctival cysts do not have the same association with hair follicles or the specific location mentioned. Chalazia arise from obstructed Meibomian glands, pterygia are growths of conjunctival tissue often related to environmental exposure, and conjunctival cysts are generally fluid-filled sacs on the conjunctiva without the