Unilateral luteoma of pregnancy mimicking a malignant ovarian mass on magnetic resonance and ultrasound

Abstract

Luteoma of pregnancy is a rare, tumorlike ovarian mass that develops during pregnancy and regresses after delivery. Generally, these masses are discovered incidentally during cesarean delivery or tubal ligation. Some of these patients will develop hirsutism or virilization during late pregnancy with or without fetal masculinization due to circulating androgens. The imaging features of this entity have been only rarely reported. An incidentally discovered luteoma of pregnancy in a 23-year-old patient during routine obstetric ultrasound is described and the image features in ultrasound and magnetic resonance (MR) imaging are discussed and compared with other studies. The patient underwent surgery to extract this mass considering the imaging findings were suspicious for neoplasia and the size and location could have potentially caused dystocia. This type of mass can mimic ovarian neoplasia and a correlation with imaging and laboratory findings can avoid an unnecessary surgical procedure during pregnancy.

Pregnancy Luteomas

“…Kao et al (9) reported that luteomas have high signal intensity on T1-weighted images and low signal intensity on T2-weighted images. However, other reports show opposite intensities (2). At this time, there is insufficient evidence that MRI provides superior or additional diagnostic information to that which can be obtained by ultrasound.…”

“…The luteomas are bilateral in 30% of cases and some times may have multiple lesions within the same ovary (7). In many cases, the tumor is interpreted as a complex heterogeneous predominantly hypoechoic mass, which may be highly vascular (2,19). Importantly, the sonographic appearance of a luteoma is not specific.…”

“…There is concern that larger masses may interfere with vaginal delivery and increase risk of dystocia (2), but this has not actually been reported. In fact, in 5 of the case reports, conservative management was successful (5,8,9,12,16).…”

A case of hypertension with virilisation during pregnancy

“…The distinction between a luteoma and other virilising tumours during pregnancy may be clinically important as the former regresses spontaneously postpartum allowing preservation of the ovary and avoidance of surgery. [7][8][9] In our case, fortunately as it was a Brenner tumour, the size of the tumour and atypical clinical feature of hypertension made us favour surgical resection over observation postpartum. It was presumed that the cholestasis of pregnancy was precipitated by the very high serum oestrogen levels.…”

Adnexal Masses: Benign Ovarian Lesions and Characterization

“…Well-vascularized adnexal masses that are pregnancy related include decidualized endometriomas and pregnancy luteomas. These may mimic malignancy, but clinical background combined with US and MRI may suggest the correct diagnosis and warrant a follow-up (Telischak et al 2008;Tannus et al 2009). Pain or an acute abdomen should alert to complications due to hemorrhage, rupture, and torsion of the adnexal mass or nongynecological pelvic conditions.…”