What Is the Adnexa? Location, Function, and Conditions

Adnexa is a medical term for the accessory structures attached to or surrounding a major organ. You will most often encounter it in gynecology, where the uterine adnexa refers to the ovaries, fallopian tubes, and their supporting ligaments and connective tissue. But the word also appears in ophthalmology (the ocular adnexa, meaning the eyelids, tear glands, and muscles around the eye) and dermatology (the skin adnexa, meaning hair follicles, sweat glands, and sebaceous glands). The shared idea across all three uses is the same: “adnexa” names the smaller structures that an organ depends on but that are not the organ itself.

Why One Word Shows Up in Three Different Specialties

The Latin root “adnexa” simply means “things joined to.” In anatomy, that concept applies wherever a central organ relies on peripheral structures to do its job. Your uterus needs tubes to capture eggs and ovaries to produce them. Your eyeball needs lids to protect it and glands to keep it moist. Your skin needs follicles and glands to regulate temperature and defend against infection. Each set of accessories earned the same umbrella label, which is why you might hear “adnexal mass” from a gynecologist and “adnexal tumor” from a dermatologist and be talking about entirely different body parts. Context always matters.

The Uterine Adnexa and What It Does

When a gynecologist says “adnexa,” they almost always mean the structures flanking the uterus on each side: the ovary, the fallopian tube, and the broad ligament that holds them in place. The ovaries produce eggs and secrete the hormones estrogen and progesterone. The fallopian tubes are where fertilization actually happens. They transport eggs from the ovary toward the uterus and create the environment needed for a sperm cell to meet an egg and for the earliest stages of embryo development to begin. The cellular lining of the tubes is tightly regulated by estrogen and progesterone, which shift the tube’s behavior across the menstrual cycle to optimize the chances of a successful pregnancy.¹

The broad ligament is less well known but still important. It is a sheet of tissue that drapes over the uterus, tubes, and ovaries, anchoring them to the pelvic sidewall and carrying blood vessels and nerves to these structures. When doctors palpate or image the “adnexa” during a pelvic exam or ultrasound, they are assessing this entire region as a unit.

Common Conditions of the Uterine Adnexa

An “adnexal mass” is any lump or swelling found in that region, and it is one of the most frequent reasons for gynecologic imaging. Most adnexal masses turn out to be benign. In surgical series, roughly a third of benign masses are epithelial lesions, about a third are functional cysts or endometriotic cysts, and close to 30% are germ-cell tumors, almost all of which are mature teratomas (sometimes called dermoid cysts).² That breakdown matters because it tells you the vast majority of masses found during an ultrasound are not cancer.

The conditions that cause trouble in the adnexa fall into a few broad categories:

Functional cysts: These form as part of the normal menstrual cycle when a follicle either fails to release an egg or fails to shrink after ovulation. They are extremely common, often painless, and frequently resolve on their own within a cycle or two.
Endometriomas: Sometimes called “chocolate cysts,” these are cysts filled with old blood that develop when endometrial tissue grows on or inside the ovary. They are associated with endometriosis and can cause significant pelvic pain.
Ectopic pregnancy: When a fertilized egg implants inside the fallopian tube instead of the uterus, the growing pregnancy can stretch or rupture the tube. This is a medical emergency.
Ovarian torsion: The ovary (sometimes along with the tube) twists on its supporting ligament, cutting off its blood supply. Torsion causes sudden, severe pain and requires urgent surgery to save the ovary.
Pelvic inflammatory disease: Infection of the tubes and ovaries, usually from sexually transmitted bacteria, can cause swelling, abscess formation, and scarring that affects future fertility.

These conditions can overlap in the same patient. One published case involved a woman who presented to the emergency department with bleeding and severe abdominal pain and was ultimately found to have a ruptured ectopic pregnancy on one side, ovarian torsion with a dermoid cyst on the other side, multiple uterine fibroids, and endometriosis, all discovered during a single diagnostic surgery.³ Another case described a young woman whose acute abdominal pain turned out to be a twisted and ruptured ovarian cyst alongside an ectopic pregnancy on the same side.⁴ These cases are unusual, but they illustrate why adnexal emergencies can be tricky to diagnose and why imaging alone sometimes is not enough.

How Adnexal Masses Are Evaluated

Transvaginal ultrasound is the standard first step for evaluating a suspected adnexal mass. It gives a detailed view of the ovaries and tubes and can characterize the internal structure of a mass: is it filled with fluid, solid tissue, or a mixture? Does it have features that suggest benign versus malignant behavior? For masses that are clearly simple cysts or clearly solid and suspicious, ultrasound works well. The challenge is the large gray zone in between. A substantial proportion of masses remain sonographically indeterminate at the point of surgical referral.⁵

To improve accuracy for these ambiguous cases, researchers have developed scoring systems and combined approaches. One recent study tested a model that paired ultrasound with contrast-enhanced ultrasound and a blood biomarker called HE4. The combined approach achieved diagnostic accuracy above 97%, outperforming ultrasound alone.⁶ The goal of all this work is to help doctors distinguish benign masses that can be watched or treated conservatively from the smaller number that need surgery or oncologic referral.

The Ocular Adnexa

In ophthalmology, the adnexa refers to the tissues and structures surrounding the eyeball: the eyelids, the conjunctiva (the thin membrane lining the inner surface of the lids and the white of the eye), the lacrimal apparatus (tear glands and drainage ducts), the extraocular muscles that move the eye, and the orbital fat and connective tissue that cushion it inside the bony socket.⁷ Together, these structures support, protect, and move the globe.

The tear film is a good example of how the ocular adnexa works as an integrated system. The lacrimal gland produces the watery component of tears, glands in the eyelids add oily and mucous layers, and the drainage ducts in the inner corner of the eye funnel used tears into the nose. The resulting three-dimensional film is essential for maintaining a smooth optical surface and protecting the cornea from drying out and from infection.⁸ When any part of that system fails, whether from dry-eye disease, a blocked tear duct, or eyelid malposition, vision can suffer even though the eyeball itself is healthy.

Infections and Inflammation of the Ocular Adnexa

The most familiar adnexal eye problems are everyday nuisances: styes (infected eyelid glands), blepharitis (chronic eyelid inflammation), and conjunctivitis (pink eye). But infections in this region can escalate. Dacryocystitis, an infection of the lacrimal sac caused by a blocked tear duct, usually presents as a painful red lump near the inner corner of the eye. In rare cases, that infection can spread behind the orbital septum, the thin sheet of tissue that separates the superficial eyelid from the deeper eye socket, and become orbital cellulitis. Orbital cellulitis threatens vision because swelling and pus can compress the optic nerve or its blood supply.⁹ The anatomy of the lacrimal sac, which sits in a relatively anterior and inferior position relative to the globe, can create a direct communication channel to the space behind the eye, making rapid surgical drainage necessary in severe cases.

People with compromised immune systems face additional risks. In patients with HIV/AIDS, the ocular adnexa can be affected by molluscum contagiosum (a viral skin infection that produces small bumps on the eyelids), herpes zoster ophthalmicus (shingles along the nerve supplying the forehead and eye), and Kaposi’s sarcoma.

Lymphoma and Other Tumors of the Ocular Adnexa

Lymphoma is the most common primary malignancy of the ocular adnexa. It can arise in the conjunctiva, the orbit, the lacrimal gland, or the eyelids. The behavior and prognosis depend heavily on the specific location. Conjunctival lymphoma tends to have the lowest rate of spreading beyond the orbit and the lowest rate of death related to the lymphoma itself. Eyelid and lacrimal gland lymphomas carry a higher risk of both spread and mortality.¹⁰

Eyelid lymphoma specifically makes up about 5% of all ocular adnexal lymphomas. Among published cases, roughly half are B-cell lymphomas and roughly half are T-cell lymphomas. The most frequent B-cell type is extranodal marginal zone lymphoma, while the most frequent T-cell type is mycosis fungoides. Both tend to present as a lump or swelling of the eyelid, though T-cell lymphomas more often show ulceration and redness.¹¹ These tumors can be mistaken for chronic blepharitis or a stubborn chalazion, sometimes delaying diagnosis for months. One case report described a man who was treated for blepharitis and chalazia over an extended period before an incisional biopsy finally revealed an extranodal marginal zone B-cell lymphoma of the eyelid skin.¹²

The Skin Adnexa

In dermatology, the skin adnexa (also called adnexa cutis) refers to the structures embedded within the skin that are not the skin itself: hair follicles, sebaceous (oil) glands, eccrine and apocrine sweat glands, and nails. These structures develop from the same embryonic tissue as the outer layer of skin, but they serve specialized functions. Hair follicles produce hair and also house stem cells that help repair wounds. Sebaceous glands secrete an oily substance called sebum that lubricates hair and skin. Eccrine sweat glands are the body’s primary cooling system, distributed across nearly the entire body surface. Apocrine glands, concentrated in the armpits and groin, produce a thicker secretion tied to scent.

The skin itself is the largest organ by surface area and functions as a barrier against water loss, ultraviolet radiation, physical trauma, and infection.¹³ The adnexal structures support that barrier while adding their own capabilities. Conditions like acne, hidradenitis suppurativa, and alopecia are all diseases of skin adnexal structures rather than the skin surface itself.

Skin Adnexal Tumors

Tumors arising from skin adnexal structures form a broad group of growths that mimic the hair follicle, the sweat gland, or the sebaceous gland under the microscope.¹⁴ The vast majority are benign. In one study from a single institution, about 83% of skin adnexal tumors were benign and 17% malignant. Tumors showing eccrine (sweat gland) differentiation were most common, followed by follicular and sebaceous types, and the head and neck was the predominant site.¹⁵

Those proportions are not universal, though. A two-center study found that sebaceous tumors were the most frequent at about 35%, followed closely by eccrine/apocrine tumors and follicular tumors. In that series, 98% of tumors were benign and only 2% malignant. Benign tumors were slightly more common in women, while the small number of malignant tumors were more common in men. Tumors larger than 20 mm were significantly more likely to be malignant.¹⁶ The practical takeaway is that a small, slow-growing bump on the face or scalp has a very high chance of being benign, but any rapidly growing or large skin lesion in that region deserves a biopsy.

Adnexal Problems in Children and Adolescents

The uterine adnexa is not just an adult concern. Ovarian masses are actually the most common abdominal masses in the pediatric population, and they can occur at any age from infancy through adolescence.¹⁷ The mix of diagnoses looks different from what doctors see in adults. In children, germ-cell tumors make up the majority of ovarian neoplasms, with the mature teratoma being the most common. By contrast, epithelial tumors dominate in adult women. The most frequent ovarian malignancy in pediatric patients is the dysgerminoma rather than the high-grade serous carcinoma that is most common in adults.

Symptoms in young patients tend to include abdominal pain, a palpable mass, nausea, and sometimes hormonal effects like early puberty or abnormal menstrual cycles.¹⁷ Diagnosis in this age group brings its own challenges. The ultrasound-based scoring systems developed for adult women do not perform identically in younger patients. One large study found that while the O-RADS ultrasound scoring system had excellent sensitivity and specificity in school-age children, its accuracy dropped somewhat in middle adolescents, with positive predictive value falling from about 71% in younger children to about 29% in middle adolescents.¹⁸ Larger masses, above 10 cm, carried a significantly higher estimated malignancy risk compared with smaller ones regardless of the scoring system used.¹⁹ Because of these diagnostic nuances, pediatric ovarian masses often require a team approach involving gynecologists, pediatric surgeons, and oncologists.

What Happens When the Adnexa Is Surgically Removed

Surgical removal of the uterine adnexa, called adnexectomy or salpingo-oophorectomy, is one of the most commonly performed gynecologic procedures. It may be done for a suspicious mass, for risk reduction in women with inherited cancer-predisposing mutations, for endometriosis, or for torsion that has destroyed the blood supply to the ovary. When one ovary is removed, the remaining ovary typically compensates, and hormonal effects are minimal. When both ovaries are removed, however, the result is surgical menopause, which happens abruptly rather than gradually.

The consequences of losing both ovaries before natural menopause extend beyond the well-known symptoms of hot flashes and sleep disruption. The early loss of ovarian hormones accelerates changes across multiple systems, including the cardiovascular system, the brain, and bone density, and affects mood, sexual function, and connective tissue health.²⁰ This is why doctors weigh the decision to remove ovaries carefully, especially in younger women. When only one ovary or tube is affected, surgeons generally try to preserve the other side.

Minimally Invasive Surgical Approaches

When adnexectomy is needed, the trend over the past two decades has been toward less invasive techniques. Traditional multi-port laparoscopy uses several small incisions in the abdomen. Single-port surgery, sometimes called laparoendoscopic single-site (LESS) surgery, aims to accomplish the same operation through a single incision, usually at the navel. A meta-analysis comparing LESS with conventional laparoscopy for adnexectomy found that blood loss was lower in the single-port group and that patients required less pain medication afterward. Operating time was slightly longer with the single-port approach, and the rate of surgical complications was somewhat higher, while hospital stay and pain scores at 24 hours were similar between the two techniques.²¹

An even newer approach is vaginal natural orifice transluminal endoscopic surgery (vNOTES), which accesses the pelvic organs through the vagina, leaving no visible abdominal scar at all. A pilot study comparing vNOTES adnexectomy with single-port laparoscopic adnexectomy found comparable surgical outcomes overall, with the vNOTES group reporting lower pain scores within 12 hours of surgery and needing fewer pain medications.²² These approaches are still being refined, and the best choice for a given patient depends on the size of the mass, the surgeon’s experience, and the patient’s anatomy and prior surgical history. The overarching direction, though, is clear: smaller incisions, faster recovery, and less postoperative pain.