ovarian cancer (risk of malignancy index (RMI))

Last reviewed 06/2021

Risk of malignancy index (RMI)

RMI I is a product of the ultrasound scan score (U), menopausal status (M) and serum CA125 level.

RMI I = U x M x CA125

  • The ultrasound result is scored 1 point for each of the following characteristics:
    • multilocular cysts, solid areas, metastases, ascites, bilateral lesions
      • U = 0 for an ultrasound score of 0 points,
      • U = 1 for an ultrasound score of 1 point,
      • U = 3 for an ultrasound score of 2-5 points

  • Menopausal status is scored as 1 = pre-menopausal and 3 = post-menopausal. The classification of 'post-menopausal' is a woman who has had no period for more than 1 year or a woman over 50 who has had a hysterectomy

  • Serum CA125 is measured in IU/ml

If RMI >= 250 then must be referred to a specialist multidisciplinary team