Meaning of adnexal mass: A finding rather than a diagnosis: something occupying the space beside the womb, which could be any of a dozen things.

Definition of adnexal mass

An adnexal mass is a lump found in the adnexa, the region beside the uterus containing the ovaries, the fallopian tubes and their supporting ligaments. The term names a location, not a cause. Ovarian cysts account for most of them, but ectopic pregnancy, infection, benign growths and cancer can all produce the same appearance on a scan.

What can it turn out to be?

CauseTypical picture
Functional ovarian cystThin-walled, fluid-filled, often settles on its own
EndometriomaOld blood inside, associated with painful periods
Mature teratomaContains fat, hair and sometimes teeth
Ectopic pregnancyBeside the uterus with a positive pregnancy test
Tubo-ovarian abscessPainful, feverish, follows pelvic infection
Ovarian cancerSolid areas, thick divisions, blood flow within

How is it assessed?

A pregnancy test comes first in anyone of childbearing age, because an ectopic pregnancy is the one cause that can turn dangerous within hours. Ultrasound follows, usually with a probe placed in the vagina for a closer view of the ovary and the fallopian tube. Features that raise concern are solid components, thick internal walls, growths projecting from the lining, blood flow inside those solid parts, and free fluid in the abdomen. Blood markers may be measured, though they rise in several harmless conditions and are read alongside the images rather than on their own.

Why does age matter so much?

Before menopause the ovary produces a follicle every month, and a follicle that fails to rupture or refills with fluid becomes a cyst. Masses of this kind are common and most disappear over a couple of cycles, so repeating the scan later is often all that is needed. After menopause the ovary is quiet and no longer forms follicles, so a new mass cannot be explained that way. The chance that it represents ovarian cancer is higher, and the assessment is correspondingly more thorough.

Used in a sentence

Pelvic ultrasound identified a right adnexal mass with mixed solid and cystic components.

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Good to know

The phrase describes where a mass sits rather than what it is, and in anyone of childbearing age a pregnancy test precedes any other interpretation.

Word origin

Where “adnexal mass” comes from

Adnexa comes from the Latin adnexa, meaning attached parts, from ad, to, and nectere, to bind.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.