International Journal of Clinical & Medical Images

Case history

A 36 years old woman in 18 weeks pregnancy with chief complaints of the lower abdominal distension and a sense of chest tightness was administrated by the out-patient service of department f obstetrics. No vaginal drainage and bleeding were observed. She had one time of gravidity and born the healthy baby with natural labor six years ago. No other diseases history was recorded. The CA125 level was 525.20 U/mL, CA199 level was 22.11U/mL and CEA level was 1.31ng/mL. On US, the reports revealed the bilateral cystic mass in the adnexal region. For the further evaluation the etiology of suspected masses, the clinicians recommended the MRI examinations with the permission of the patient. MR imaging was performed using a 1.5-T MR system (Magnetom Avanto, Siemens, Erlangen, Germany) with a phased-array coil. On MRI, the bilateral giant, lobular cystic mass occupied the whole abdominal cavity with homogeneous hypointensity on T1-weighted imaging (T1WI) and hyperintensity on T2-weighted imaging (T2WI) (Figure 1). For the safe of fetal, no contrast material was used in this case. The patient was performed the laparoscopic surgery three days after MRI performance. Cyst aspiration was undergone under the laparoscopic surveillance. The final pathological diagnosis was the bilateral ovarian luteinizatied cysts. The informed content from the patient with permission of usage of related MRI images was obtained during preparation of this manuscript.

Figure 1
A 36-year-old woman in second trimester with bilateral ovarian luteinizatied cysts. On axial T1WI (A) and T2WI (B), the giant cystic mass(*) displayed as the homogeneous low signal on T1WI and high signal on T2WI; on coronal T2WI (C), the giant cystic masses(arrowhead) was more clearly outlined resembling the inflatable ovarian follicles. The residual ovarian stroma centrally located in the mass. Note, the pregnant uterus (short arrow) was revealed in the centre of pelvic cavity. On diffusion weighted Imaging (DWI) and Apparent Diffusion Coefficient (ADC) map, the mass displayed as the homogenous intermediate signal on DWI (D) similar to muscle signal and high signal on ADC map (E).

Discussion

Theca-lutein cyst ( Hyperreactio luteinalis) is a rare benign physiological ovarian enlargement with multiple theca lutein cysts caused by increased human chorionic gonadotropin (hCG) serum levels. It occurs during the luteal phase of the menstrual cycle or during early pregnancy[1,2]. Such condition is also associated with ovarian hyperstimulation syndrome (OHSS), an iatrogenic complication following drug therapy (ovulation treatment) for infertility [1,3]. Theca-lutein cyst usually accompany with the gestational trophoblastic disease, multiple pregnancy, ovulation treatment and oral estrogen[3]. Bilateral giant theca-lutein cysts secondary to normal pregnancy as in this reported case is particularly uncommon. Here, we firstly reported MRI and DWI findings of the theca-lutein cyst in pregnant woman in the second trimester. On MRI, the accumulation of expanded follicles in each of ovary made it as the multilocular cystic tumors. However, the residual ovarian stroma(solid component) may rend them to be differentiated from ovarian cystadenoma.

References
1. Yacobozzi M, Nguyen D, Rakita D (2012) Adnexal masses in pregnancy. Seminars in Ultrasound, CT and MRI 33:55-64.

2. Takeuchi M, Matsuzaki K (2011) Magnetic resonance manifestations of hyperreactio luteinalis. Journal of Computer Assisted Tomography 35:343-346 .

3. Ackerman S, Irshad A, Lewis M, Anis M (2013) Ovarian cystic lesions: A current approach to diagnosis and management. Radiologic Clinics of North America 51:1067-1085.

Corresponding author

He Zhang
Department of Radiology
Obstetrics and Gynecology Hospital
Fudan University
China