The adnexal region is a specific anatomical area within the female pelvis, often referenced in gynecological and radiological contexts. The term adnexa is derived from Latin, meaning “appendages” or “connected parts,” and it refers to the structures located adjacent to the uterus. Understanding this region is foundational to comprehending the reproductive system, as it houses the organs responsible for producing eggs and transporting them for potential fertilization. It is a common site for various medical conditions, ranging from temporary changes to those requiring urgent intervention.
Defining the Adnexal Region
The adnexal region is an anatomical space situated on both the right and left sides of the uterus. It is positioned laterally, extending outward from the main body of the uterus toward the pelvic sidewalls, deep within the true pelvis. The broad ligament, a wide fold of peritoneum, encases the adnexal components and helps define their boundaries. These structures are positioned superiorly and laterally to the bladder and anteriorly to the rectum.
Primary Structures Contained Within the Adnexa
The adnexal space on each side of the uterus is primarily occupied by the ovaries and the fallopian tubes. These two structures are considered the main components of the adnexa. The ovaries are small, almond-shaped glands responsible for producing female hormones like estrogen and progesterone, and for storing and releasing eggs. The fallopian tubes, also known as uterine tubes, are muscular canals that extend toward the ovaries. Their primary function is to capture the egg released during ovulation and transport it toward the uterus, where fertilization typically occurs. Supporting these organs is a network of connective tissues, suspensory ligaments, blood vessels, nerves, and lymphatic channels.
Common Clinical Findings in the Adnexa
The term “adnexal mass” is a general description used when imaging reveals a growth or swelling in this region. Such masses are common findings, and the majority are benign, meaning they are non-cancerous. A significant portion of these masses are ovarian cysts, which are fluid-filled sacs that develop on the ovary. Functional cysts, such as follicular or corpus luteum cysts, arise as a normal part of the menstrual cycle and usually resolve spontaneously without intervention. Other benign masses include endometriomas, associated with endometriosis, and dermoid cysts, which contain various tissues like hair or fat.
Serious Adnexal Conditions
Ectopic pregnancy occurs when a fertilized egg implants and begins to grow outside the main cavity of the uterus, most commonly within a fallopian tube, presenting as an adnexal mass. Adnexal torsion is a serious condition where the ovary, sometimes along with the fallopian tube, twists around its supporting ligaments, cutting off its blood supply. This torsion is a medical emergency that causes sudden, severe pelvic pain and requires immediate surgical correction. Pelvic inflammatory disease (PID) is an infection that can travel upward, severely affecting the fallopian tubes and sometimes leading to the formation of a tubo-ovarian abscess within the adnexa.