What is the diagnostic approach for a female patient over 50 with new-onset bloating and abdominal fullness, considering a potential diagnosis of ovarian cancer?

Diagnostic Approach for Ovarian Cancer in Women Over 50 with Bloating and Abdominal Fullness

In a woman over 50 presenting with new-onset bloating and abdominal fullness, immediately obtain serum CA-125, transvaginal and transabdominal ultrasound by an expert examiner, and CT of chest/abdomen/pelvis with contrast to evaluate for ovarian cancer. 1

Initial Clinical Assessment

Symptom Recognition

• Bloating, abdominal fullness, and pelvic pain occurring more than 12 times per month with recent onset are highly suspicious for ovarian cancer in women over 50. 1, 2, 3
• Additional concerning symptoms include early satiety, nausea, anorexia, dyspepsia, constipation, diarrhea, urinary frequency, and vaginal bleeding. 1
• In advanced disease, ascites causes progressive abdominal distension; pleural effusions cause dyspnea and occur in 50-70% of stage IV cases. 1, 4

Physical Examination Priorities

• Palpate for pelvic/adnexal masses (though sensitivity is low, negative findings should not deter workup). 2
• Assess for ascites by percussion and fluid wave. 1
• Examine for inguinal, supraclavicular, and axillary lymphadenopathy indicating metastatic spread. 1, 5

Mandatory Laboratory Testing

Tumor Markers

• Serum CA-125 is elevated in ~85% of advanced ovarian cancer but only ~50% of stage I disease. 1
• CA-125 lacks specificity—can be elevated in endometriosis, ovarian cysts, pelvic inflammatory disease, and other benign conditions. 1
• Add serum CEA and CA 19-9 if mucinous histology is suspected; a CA-125/CEA ratio <25:1 suggests gastrointestinal metastasis rather than primary ovarian cancer. 1, 5
• Consider endoscopy if CEA or CA 19-9 are elevated to exclude gastrointestinal primary. 1

Imaging Algorithm

First-Line Imaging

• Transvaginal and transabdominal ultrasound by an expert examiner is the initial imaging modality of choice. 1
• Ultrasound-based diagnostic models (IOTA Simple Rules or IOTA ADNEX) are superior to CA-125 alone or Risk of Malignancy Index for distinguishing benign from malignant masses. 1
• Malignant features on ultrasound: complex mass with solid and cystic components, internal septations, papillary projections, irregularity, bilaterality, ascites, peritoneal implants. 1, 2

Staging and Surgical Planning Imaging

• CT of chest, abdomen, and pelvis with contrast is mandatory to complete clinical staging and guide surgical planning. 1
• CT identifies peritoneal metastases, omental caking, lymphadenopathy, and pleural effusions. 5, 6
• MRI may be useful for indeterminate lesions on ultrasound to better characterize malignant features. 1
• PET/CT is not recommended for primary diagnosis due to high false-positive rates but may help with indeterminate lesions. 1

Definitive Diagnosis

Tissue Acquisition

• Definitive diagnosis requires pathological examination by an expert pathologist of tissue from diagnostic biopsy or surgical specimen. 1
• Avoid fine-needle aspiration in presumed early-stage disease to prevent capsule rupture and peritoneal spillage of malignant cells. 1
• FNA may be necessary only in patients with bulky unresectable disease who are not surgical candidates. 1

Cytological Assessment

• Obtain cytological assessment of ascites (if present in early-stage disease) and pleural fluid (if safely accessible) for complete staging. 1

Critical Pitfalls to Avoid

Common Diagnostic Errors

• Do not dismiss symptoms based on normal CA-125 alone—up to 50% of early-stage ovarian cancers have normal CA-125 levels. 1, 4
• Negative pelvic examination does not exclude ovarian cancer; proceed with imaging if symptoms are present. 2
• In women over 50 with new persistent bloating/fullness, ovarian cancer must be in the differential even without a palpable mass. 4, 3

Urgent Scenarios Requiring Immediate Action

• Oxygen saturation <92% requires immediate arterial blood gas analysis within 1 hour to assess for hypoxia from pleural effusion. 4
• Hypotension with abdominal distension requires immediate exclusion of massive ascites, pleural effusion, or sepsis. 4
• Obtain comprehensive metabolic panel, complete blood count, and chest X-ray urgently (within 4-6 hours) if respiratory symptoms or fever present. 4

Referral Pathway

When to Refer to Gynecologic Oncology

• Refer immediately to a gynecologic oncologist if ultrasound shows malignant features, ascites is present, or CA-125 is elevated with concerning imaging. 5, 7
• Adnexal mass >6 cm on ultrasound or findings persisting >12 weeks warrant gynecologic oncology referral. 2
• Surgical staging requires midline laparotomy with comprehensive evaluation per FIGO guidelines, best performed by a gynecologic oncologist at a specialized cancer center. 1, 5