Persistent bloating, a raised CA125 and a complex ovarian cyst
Ms C is a 47-year-old project manager. She has a 3-year history of irritable bowel syndrome diagnosed in primary care. Over the last 8 weeks she has noticed persistent bloating, early satiety and urinary frequency, and her trousers feel tight. She has no rectal bleeding, weight loss or family history of ovarian or breast cancer. Examination reveals a non-tender, mobile pelvic mass on bimanual examination. A CA125 taken last week is 58 U/mL (reference <35). A transvaginal ultrasound reports a 6 cm complex cyst with thick septations and solid areas, with normal ovarian tissue separate. She is tearful and says, 'It's just my IBS, I don't want to be poked about. Can we repeat the blood test in six months?' The practice has a 2-week wait pathway and a direct-access gynae oncology clinic.
1. How would you interpret the CA125 and ultrasound, and calculate/interpret the RMI? What is your referral decision?
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Interpretation. A CA125 of 58 U/mL is raised but non-specific; it can be elevated by menstruation, endometriosis, fibroids, liver disease and heart failure. The ultrasound is more concerning: a 6 cm complex cyst with thick septations and solid areas is suspicious, and normal ovarian tissue separate does not exclude malignancy. The RMI is CA125 (58) × menopausal status (premenopausal = 1) × ultrasound score (U = 3, because multilocular, solid areas and possibly other features) = 174. An RMI above 250 is high risk, but 174 is not reassuring and the scan alone meets the criteria for urgent referral.
Decision. Refer on the 2-week suspected cancer pathway to gynaecological oncology. Do not repeat CA125 in six months and do not treat as IBS. Request a CT chest/abdomen/pelvis if locally agreed, but do not delay the referral for it. Also check FBC, renal and liver function. The key point is that the ultrasound, not the CA125 alone, drives the referral.
2. How would you explain the findings and safety-net her, given her reluctance?
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Explanation. Acknowledge her fear and her long IBS history. Use plain language: 'The blood test is only a clue; the scan shows a cyst that has features we cannot explain as benign, so it needs a specialist look.' Avoid saying she definitely has cancer; say the risk is uncertain and the purpose of referral is to rule it out. Check understanding and invite questions. Offer a chaperone, written information and a contact number.
Safety-netting. Ask her to return urgently if she develops severe abdominal pain, vomiting, fever, rapid abdominal swelling, breathlessness, or bleeding. Tell her the referral should be within two weeks and give the clinic details. Document the discussion, her concerns and her agreement. If she remains reluctant, explore the reason (fear, work, caring responsibilities) and offer to speak to a relative with her consent. Do not collude with a plan to wait.
3. What would you do if she declined referral?
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If she declines. First assess capacity: can she understand, retain, weigh and communicate the decision? She likely can. Explain the consequences of delay, including the possibility of advanced disease. Offer a further appointment, a second opinion, and involvement of a specialist nurse. Document the discussion in her notes, including the risks explained and her reasons. Inform the GP and the gynae oncology team so the door remains open. If there are safeguarding concerns about a dependent, follow local policy. You cannot force investigation, but you must not abandon her; arrange a review and clear safety-net advice.