Gynaecology oncology is one of the sub-specialities within the discipline of obstetrics and gynaecology and is now available in most major hospitals. With the availability of this service, it has become possible for the general obstetricians and gynaecologists to request assistance when performing difficult surgical procedures. These requests are usually from colleagues within the hospital but they can also be from gynaecologists in affiliated district hospitals. Patients presenting with a complex pelvic mass diagnosed by ultrasound imaging is a common cause of referral from gynaecologists in district hospitals. The main fear among gynaecologists in the peripheral hospitals is to inadvertently operate on a patient with a malignant tumour. There is now good evidence that patients with ovarian cancer have better outcomes if the primary surgery is performed by a qualified gynaecological oncologist. In the John Hunter Hospital, Hunter New England Centre for Gynaecological Cancer (a tertiary referral hospital), we accept referrals from gynaecologists in the peripheral hospitals and at times this can be a daunting task. While accommodating these referrals, it is important to have a system in place so as not to delay surgical intervention in patients with established gynaecological cancers. The use of a risk of malignancy index can identify patients at high risk of malignancy pre-operatively and thus allow appropriate triage. Appropriate use of the Risk Malignancy Index (RMI) has been shown to reduce the number of benign cases operated on in busy gynaecological oncology units. In 1990, Jacobs first described the Malignancy Risk Index, where he detailed the value of clinical features, realtime ultrasonography and serum CA 125 measurement in the diagnosis of patients admitted with a complex pelvic mass. He calculated the RMI as the product of the serum CA 125 level (U/mL), ultrasound scores and the menopausal status. In the following years RMI 2 and RMI 3, which are modifications to the original model were introduced. These were first described by Tingulstad in 1996 (RMI 2) and in 1999 (RMI 3). Comparison studies assessing the performance of these three RMI’s in different populations have been published, but none has been performed in an Australian population.
Australian & New Zealand Journal of Obstetrics & Gynaecology Vol. 50, Issue 1, p. 77-80