Adnexal mass

An adnexal mass is a benign or malignant mass of the ovary, fallopian tube, or surrounding tissues. Although most adnexal masses have a benign cause (e.g., functional ovarian cyst, endometrioma, benign ovarian tumor), malignancy is an important consideration. While most adnexal masses in adults are asymptomatic and incidentally detected, some patients present with pelvic pain, vaginal bleeding, or systemic symptoms. Patients with acute symptoms of potentially life-threatening diagnoses (e.g., ectopic pregnancy, ovarian torsion) should receive immediate evaluation and management. Initial diagnostics include tests to rule out ectopic pregnancy, if appropriate, and transvaginal ultrasound (TVUS). Depending on the suspected etiology, additional testing may include diagnostics for pelvic inflammatory disease (PID) and ovarian tumor markers. Management depends on the suspected underlying cause and presence of symptoms. Patients with likely benign etiologies can usually be managed expectantly if they are asymptomatic. Symptomatic patients or those with indeterminate findings or features suggestive of malignancy should be referred to a gynecologic oncologist for surgical evaluation.

Benign causes ^[1][2]

• Functional ovarian cyst
• Endometrioma
• Polycystic ovary syndrome (PCOS)
• PID (e.g., tubo-ovarian abscess)
• Ovarian torsion
• Benign ovarian tumors
  • Ovarian cystadenoma (serous or mucinous)
  • Brenner tumor
  • Dermoid cyst
  • Struma ovarii ^[3]
  • Ovarian fibroma
  • Theca cell tumor
  • Sertoli-Leydig cell tumor
• Hydrosalpinx
• Uterine leiomyoma
• Müllerian anomalies

Most adnexal masses are benign. ^[1][3]

Malignant causes ^[1][2]

• Primary ovarian cancer
  • Ovarian epithelial carcinoma
  • Ovarian germ cell tumors
  • Granulosa cell tumor
• Metastatic cancer (Krukenberg tumor)

Ovarian epithelial carcinoma most commonly occurs in postmenopausal individuals. ^[1]

• Assess for hemodynamic instability.
• Immediate hemodynamic support and management of hemorrhagic shock if needed
• Urgent OB/GYN consult for consideration of surgical intervention in patients with: ^[3]
  • Hemodynamic instability
  • Clinical features of peritonitis
  • Clinical features of bowel obstruction
  • Clinical features of acute urinary tract obstruction
  • Clinical features of ovarian torsion
  • Clinical features of ectopic pregnancy
• See also “Initial management of pelvic pain.”

Focused history ^[1][2][3]

• Comprehensive gynecologic history, including:
  • Risk factors for ovarian cancer
  • Contraception history
  • Menstrual history and pregnancy status
  • Family history of breast or ovarian cancer or genetic syndromes (e.g., Lynch syndrome)
• Associated symptoms
  • Abdominal or pelvic pain and associated characteristics
  • Symptoms of hyperestrogenism
  • Vaginal discharge or bleeding
  • Gastrointestinal symptoms (e.g., bloating, early satiety, changes in bowel habits)
  • Constitutional symptoms
  • Urinary symptoms (e.g., frequency)

Most adnexal masses are asymptomatic and detected incidentally. ^[1][3]

Examination ^[1][2]

• General examination
  • Vital signs: to assess for emergent causes of adnexal mass (e.g., signs of infection, signs of ruptured ectopic pregnancy)
  • Lymph node examination, including axillary, inguinal, and neck nodes
  • Lung auscultation ^[2]
  • Abdominal examination, including assessment for ascites
• Pelvic examination
  • Bimanual examination
  • Rectovaginal examination as indicated (e.g., to assess lesion extent)
  • Speculum examination as indicated (e.g., to assess for infection)

In patients with a unilateral tender adnexal mass, consider ovarian cyst rupture, ovarian torsion, ectopic pregnancy, and tubo-ovarian abscess. ^[4]

Palpable masses that are irregular, nodular, firm, fixed, or associated with ascites are concerning for malignancy, although benign conditions (e.g., endometriosis, chronic PID, uterine leiomyomas) may manifest similarly. ^[1][2]

Approach ^[1][2]

• All individuals who can become pregnant: pregnancy test
• Pregnant individuals
  • Diagnostics for ectopic pregnancy
  • Ectopic pregnancy excluded: diagnostics as for nonpregnant individuals
• Nonpregnant individuals
  • Imaging (first-line: TVUS)
  • Consider laboratory testing based on clinical presentation, e.g.:
    • Suspected infection: CBC and diagnostics for PID
    • Ovarian tumor markers to assess risk of malignancy
  • Refer to a specialist for confirmatory tests if malignancy is suspected.

Although most adnexal masses are benign, rule out malignancy in all patients. ^[1][2]

Invasive diagnostics are not routinely required for suspected benign adnexal masses. Fine-needle aspiration is typically contraindicated because it can directly spread tumor cells to the peritoneum. ^[1]

Imaging ^[1][5][6]

Ultrasound

• Modalities
  • TVUS
    • First-line imaging modality in all patients
    • Doppler ultrasound is typically performed at the same time.
  • Transabdominal ultrasound
    • Adjunct to TVUS ^[1]
    • Alternative to TVUS ^[1]
• Findings
  • Findings of the underlying cause may be present.
  • Specific ultrasound features may suggest benign or malignant etiologies. ^[6][7]

Additional imaging modalities ^[1][5]

• MRI pelvis without and with IV contrast: indicated when ultrasound is inconclusive
• CT
  • CT pelvis: not routinely recommended to evaluate an undifferentiated adnexal mass
  • CT chest, abdomen, and pelvis: may be used for cancer staging in patients with confirmed pelvic malignancy

Consider ovarian cancer in patients with extraovarian findings such as retroperitoneal lymphadenopathy and omental caking on cross-sectional imaging. ^[2]

FDG-PET/CT cannot reliably distinguish between benign and malignant adnexal lesions and is not recommended in the initial diagnostic workup for an undifferentiated adnexal mass. ^[5]

Ovarian tumor markers ^[1][2][3]

• CA 125: Consider obtaining in all patients, especially postmenopausal patients and those with ultrasound features concerning for ovarian malignancy.
  • CA 125 levels are elevated in ∼ 80% of malignant epithelial ovarian tumors; , and in other malignancies.
  • CA 125 levels may also be elevated in benign gynecologic conditions (e.g., PID, endometriosis).
  • Interpretation of results
    • Postmenopausal women: Levels > 35 U/mL should raise concern for malignancy. ^[1]
    • Premenopausal women: no established cutoff; very high levels should raise suspicion for malignancy.
• AFP, β-hCG, and LDH (germ cell tumor marker): Obtain if clinical or imaging findings are suggestive of ovarian germ cell tumors.
• Inhibin (granulosa cell tumor marker): Obtain in selected patients, e.g., those with:
  • Signs of hyperestrogenism
  • Vaginal bleeding and a solid pelvic mass
• Tumor marker panels: may be considered by a specialist prior to surgery ^[2]

The positive predictive value and specificity of CA 125 for malignancy are higher in postmenopausal patients (with or without an adnexal mass) than in other patient groups. ^[1]

Risk stratification ^[1][2][3]

• Risk stratify the likelihood of malignancy in all patients, based on clinical evaluation and diagnostic findings.
• Features that suggest an indeterminate or malignant etiology:
  • Postmenopausal patients with CA 125 > 35 U/mL
  • Premenopausal patients with a significantly elevated CA 125 level
  • Elevation of ovarian tumor markers disproportionate to the clinical context
  • Abnormal serum biomarker panels
  • Ultrasound features concerning for ovarian cancer
  • Clinical or imaging features of metastatic disease (secondary ovarian cancer)
  • Nodular or fixed pelvic mass
  • Increased likelihood of malignancy on formal risk stratification tools
• Formal tools may aid risk stratification. ^[1][2]

Indeterminate or suspected malignant etiology ^[1][2][3]

• Refer patients to gynecologic oncology for further evaluation and management.
• See “Diagnostics for ovarian tumors” and “Management of ovarian cancer” for details.

Likely benign etiology ^[1][2][3]

Symptomatic patients

• Refer to gynecology or gynecologic oncology for consideration of surgery. ^[1]
• Fertility-preserving procedures are recommended for individuals planning future pregnancy.
• See relevant articles for details (e.g., “Ovarian torsion,” “Ovarian cysts”).

Asymptomatic patients

• Expectant management is usually appropriate in all patients.
• Perform surveillance imaging with the same modalities as for initial diagnostics of an adnexal mass. ^[5]
  • There is insufficient data on the optimal frequency and duration of surveillance imaging. ^[6]
  • For a persistent or enlarging mass, refer to gynecology or gynecologic oncology for further evaluation.

Expectant mangement with ultrasound surveillance is usually appropriate in asymptomatic patients with an adnexal mass of likely benign etiology. ^[1][3]

Adnexal mass in children ^[1][2][3]

• Etiology
  • Etiologies are similar to those in adults.
  • Ovarian germ cell tumors are the most common ovarian cancer in children and adolescents. ^[1]
  • Although most adnexal masses in adults and children are benign, the likelihood of malignancy is higher in children. ^[1][3]
• Clinical evaluation
  • Generally the same as in adults; see “Clinical evaluation of adnexal mass.”
  • Inquire confidentially about sexual activity.
  • Children are more likely than adults to be symptomatic (e.g., pelvic pain, menstrual irregularities, precocious puberty). ^[17]
• Diagnostics: Approach is generally the same as in adults (see “Diagnostics for adnexal mass”), with some modifications detailed here.
  • Imaging: Transabdominal ultrasound is recommended instead of TVUS for prepubertal children or those who have not had vaginal intercourse.
  • Tumor markers
    • AFP, β-hCG, and LDH (germ cell tumor marker): all patients
    • Inhibin (granulosa cell tumor marker): patients with signs of precocious puberty
    • CA 125: not routinely obtained
• Management
  • Approach is generally the same as in adults; see “Management of adnexal mass.”
  • Fertility-preserving procedures should be prioritized.

Although most adnexal masses in children are benign, the likelihood of malignancy is higher in children than in adults. ^[1][3]

Adnexal mass in pregnancy ^[1][18]

• Etiology
  • Adnexal mass occurs in up to 2–3% of pregnancies. ^[1][2][18]
  • Most adnexal masses in pregnancy are benign and identified incidentally on prenatal ultrasound.
  • In addition to general causes of adnexal mass, causes specific to pregnancy include:
    • Theca lutein cyst
    • Pregnancy luteoma
    • Ectopic pregnancy
    • Heterotopic pregnancy
• Diagnostics: Approach is generally the same as in premenopausal adults (see “Diagnostics for adnexal mass”), with some modifications detailed here.
  • Imaging
    • Transabdominal ultrasound may be useful as an adjunct to TVUS later in pregnancy. ^[1]
    • If MRI is performed, gadolinium contrast is not recommended.
  • Tumor markers
    • Lower specificity for malignancy in pregnancy ^[18]
    • Consult specialists if malignancy is suspected.
• Management
  • Approach is generally the same as in adults; see “Management of adnexal mass.” ^[18]
  • Timing of surgery if indicated: early second trimester ^[19]

Ovarian tumor markers may be abnormal in pregnancy for reasons other than malignancy (e.g., CA 125 can be elevated in an uncomplicated first-trimester pregnancy). ^[1][18]

Removal of an adnexal mass should ideally take place in the early second trimester to avoid damage to the corpus luteum. Progesterone, which is essential for maintenance of pregnancy, is secreted by the corpus luteum prior to this time, but subsequently by the placenta. ^[19]

Nongynecologic causes of pelvic mass include: ^[1]

• Complicated diverticulitis
• Periappendiceal abscess
• Pelvic kidney
• Bladder diverticulum
• Crohn disease ^[18]
• Retroperitoneal sarcoma
• Gastrointestinal cancers
• Metastatic cancer (e.g., breast, gastric, colorectal)