The lacrimal caruncle, or caruncula lacrimalis, is the small, pink, globular nodule at the inner corner (the medial

canthus The canthus (pl. canthi, palpebral commissures) is either corner of the eye where the upper and lower eyelids meet. More specifically, the inner and outer canthi are, respectively, the medial and lateral ends/angles of the palpebral fissure. Th ...

) of the eye. It consists of tissue types of neighbouring eye structures. It may suffer from lesions and

allergic Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...

inflammation.

Structure

The lacrimal caruncle is found at the medial

of the eye. It consists of

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...

hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...

sebaceous gland A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest number ...

sweat gland Sweat glands, also known as sudoriferous or sudoriparous glands, , are small tubular structures of the skin that produce sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial sur ...

s, accessory lacrimal tissue and other tissues that are present in the skin and

accessory lacrimal glands Krause's glands, Wolfring's glands (or Ciaccio's glands) and Popov's gland are the accessory lacrimal glands of the lacrimal system of human eye. These glands are structurally and histologically similar to the main lacrimal gland. Glands of Kra ...

. Its non-keratinized

epithelium Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellul ...

resembles the

conjunctiva The conjunctiva is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium ...

l epithelium.

Clinical significance

Lesions

The lacrimal caruncle may have a lesion. This can have any one of a number of causes, which may be difficult to diagnose. Cancer is a rare cause. These lesions include

papillomas A papilloma (plural papillomas or papillomata) ('' papillo-'' + '' -oma'') is a benign epithelial tumor growing exophytically (outwardly projecting) in nipple-like and often finger-like fronds. In this context, papilla refers to the projection c ...

and oncocytomas.

Allergies

With ocular

allergies Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...

, the lacrimal caruncle and the plica semilunaris of the conjunctiva may be inflamed and

pruritic Itch (also known as pruritus) is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to be classified as any one type of sensory experience. Itch has many similarities to pain, and while both are unpleasan ...

(itchy) due to

histamine Histamine is an organic nitrogenous compound involved in local immune responses, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Since histamine was discovered in ...

release in the tissue and tear film.

Other Diagnoses

Sweat glands and oil glands are contained in the caruncle of the eye (Lacrimal caruncle in medial canthus). As with all oil glands, lacrimal caruncles can become clogged, causing a pimple, whitehead, or pustule beneath the skin. Clogged oil and sweat glands in the caruncle can affect tear ducts. Treatment for dry eyes due to clogged glands includes refraining from rubbing the eyes and rinsing the eyes with clear water frequently during the day, either with clean hands or a spray faucet. Anti-bacterial eye drops may also be prescribed. If the pustules enlarge, an oral antibiotic may be prescribed. If lesions such as cysts form, they must be surgically drained; this operation is rarely necessary. Levy, J., Ilsar, M., Deckel, Y. et al. Lesions of the caruncle: a description of 42 cases and a review of the literature. Eye 23, 1004–1018 (2009). https://doi.org/10.1038/eye.2008.316 If it affects the tear sac it may be Dacryocystitis.

References

Additional images

File:Slide2www.JPG, Extrinsic eye muscle. Nerves of orbita. Deep dissection Lacrimal Caruncle Lesion.jpg, Small white lesion on lacrimal caruncle, most likely a cyst Human eye anatomy {{anatomy-stub