What is the best course of action for a 79-year-old female with a uterus experiencing lower abdominal pain?

Management of Lower Abdominal Pain in a 79-Year-Old Woman with Intact Uterus

For a 79-year-old postmenopausal woman with lower abdominal pain and an intact uterus, CT abdomen and pelvis with IV contrast is the initial imaging of choice, as it provides comprehensive evaluation of both gynecologic and non-gynecologic causes with approximately 88% overall accuracy. 1

Initial Clinical Assessment

The differential diagnosis in this population differs significantly from reproductive-age women:

• Most common gynecologic causes include uterine fibroids (second most common), ovarian cysts (one-third of cases), pelvic infection (20% of cases), and ovarian neoplasm (8% of cases) 1
• Critical diagnosis to exclude: Pyometra, which presents with nonspecific lower abdominal pain in elderly women and may lack the classic triad of fever and vaginal discharge 2
• Non-gynecologic causes are equally important, including diverticulitis, urinary tract pathology, gastrointestinal disorders, and vascular conditions 1

Imaging Algorithm

First-Line Imaging: CT Abdomen and Pelvis with IV Contrast

CT with IV contrast should be performed as the initial study because:

• It evaluates both gynecologic and non-gynecologic pathology simultaneously in this age group where the differential is broad 1
• Sensitivity of 74-95% and specificity of 80-90% for adnexal torsion 1
• Superior detection of tubo-ovarian abscess with specific findings: thick-walled adnexal fluid collection, septations, gas bubbles, and thickened round ligament 1
• Identifies pyometra as a cystic structure within the uterine fundus, which is critical in elderly women 2
• Detects fibroid complications including torsion, prolapse, or degeneration 1
• Evaluates for diverticulitis, which is common in this age group 1

When to Consider Alternative Imaging

Ultrasound (transvaginal or transabdominal) may be appropriate if:

• Gynecologic etiology is strongly suspected based on pelvic examination findings 3
• Patient cannot receive IV contrast due to renal insufficiency 1
• However, ultrasound has lower sensitivity (70%) compared to CT (89%) for urgent diagnoses in adults with abdominopelvic pain 3

MRI without and with IV contrast is reserved for:

• Problem-solving after initial CT or ultrasound 3
• Suspected endometriosis or fistulizing disease 3
• Not appropriate as initial imaging due to time constraints, motion artifacts in symptomatic patients, and lower sensitivity for extraluminal air 1

Specific Conditions Requiring Urgent Intervention

Pyometra

• High index of suspicion in postmenopausal women with intact uterus and lower abdominal pain 2
• May present without fever or vaginal discharge 2
• CT shows enlarged uterus with fluid collection; ultrasound confirms diagnosis 2
• Requires endometrial sampling and drainage 2

Fibroid Complications

• Acute pain from torsion of pedunculated fibroid, prolapse of submucosal fibroid, or infarction/hemorrhage 1
• More common cause of pain in postmenopausal than premenopausal women 1

Ovarian Pathology

• Ovarian torsion: CT shows asymmetrically enlarged ovary with twisted pedicle, abnormal enhancement, and deviation of uterus to affected side 1
• Ovarian neoplasm: Accounts for 8% of acute pelvic pain in this population 1

Pelvic Infection

• Tubo-ovarian abscess: CT demonstrates thick-walled adnexal mass with septations; right ovarian vein entering right pelvic abscess has 100% specificity and 94% sensitivity 1
• Endometritis with cervical stenosis can occur in postmenopausal women 1

Critical Pitfalls to Avoid

• Do not rely on pelvic examination alone: Physical examination has limited sensitivity for serious pathology and screening pelvic examinations in asymptomatic women lead to unnecessary procedures in 1.5% of cases 1
• Do not assume benign etiology: While pelvic organ prolapse is common and typically not painful 4, it can rarely cause small bowel obstruction requiring intervention 5
• Do not delay imaging: In postmenopausal women with acute pain, imaging is essential as clinical presentation is often nonspecific 2
• Do not use plain radiography as initial test: Radiography has very limited utility and CT is far more accurate 1
• Do not forget non-gynecologic causes: Approximately 15% of postmenopausal women with pelvic pain have non-gynecologic etiologies including urinary, gastrointestinal, and vascular pathology 1

Management Considerations

Once imaging identifies the etiology:

• Surgical consultation for ovarian torsion, complicated fibroids, or pyometra requiring drainage 1, 2
• Gynecology referral for ovarian masses requiring further characterization 1
• Antibiotics for confirmed pelvic infection (tubo-ovarian abscess, endometritis) 1
• Conservative management with pessary for pelvic organ prolapse if symptomatic 5

Pain management with NSAIDs (ibuprofen 400 mg every 4-6 hours) is appropriate for mild to moderate pain while diagnostic workup proceeds 6, but definitive treatment depends on identifying the underlying cause through imaging.