4 Discussion
We calculated the occurrence of pregnancy luteoma in our hospital to be approximately 7.9 per 100,000 pregnancies. Since all of the cases described herein were discovered incidentally at cesarean section and there was no information relating to the possible number of cases in mothers who underwent vaginal deliveries (and accounting for the majority of the total number of women experiencing labor), the estimated morbidity must be much higher than that reported in the existing literature (200 cases).1
As confirmed by other researchers, these lesions are typically discovered at or near term and are rarely symptomatic.2 All of the patients described herein underwent ultrasonographic scans of their ovaries during early and mid-gestation; there were no abnormal findings, thus suggesting that the pregnancy luteomas grew quickly during the third trimester of pregnancy. Hyperandrogenism may be a valuable clinical symptom to help with diagnosis; however, reports indicate that only a minority of cases showed maternal signs of virilization.1 Unfortunately, we did not perform androgen testing in these patients; we found that masculinization only affected the patient out of the seven with the largest ovarian mass; it is possible that the symptoms of this patient were related to tumor size.
Does pregnancy luteoma have adverse effects on pregnancy outcome? Previous reports suggest that pregnancy luteoma may coexistence with such conditions as polycystic ovarian syndrome and diabetes.1,15,16 In our cohort of patients, 2 of the 7 were diagnosed with gestational diabetes mellitus; however, none of these patients had a history of diabetes or polycystic ovarian syndrome. We calculated BMI and weight gain during pregnancy for all 7 women; these data were in line with other pregnant women.17 In addition, we diagnosed oligohydramnios in two cases. Coincidentally, the only patient showing masculinization in our study developed pre-eclampsia; there are case reports in the literature involving patients who developed pre-eclampsia and had masculinization.1,18–20 It may be possible that there is an unknown relationship between pregnancy luteoma, gestational hypertension, and masculinization. Another interesting point is that in contrast to most other reports, which reported that patients with pregnancy luteoma were usually multiparous, 6 out of the 7 reported in the current paper were primigravidae; our findings are therefore in line with the review published by Kaitlin Masarie.1 The clinical significance of parity, if there is any, remains unknown.
Successive pregnancy luteomas that are associated with maternal hyperandrogenism may cause phenotypic variation and masculinization of the external genitalia in female infants.10,21 These effects can be serious. We will continue to follow up these newborns to investigate the possibility of long-term effects.
The gross characteristics of our patients were generally similar to those recorded in the literature. The size of pregnancy luteomas can range from microscopic to 20 cm in diameter. The gross characteristics of these luteomas have been described as soft, yellow-white to red-tan, fleshy, and circumscribed areas with frequent hemorrhagic foci.2 However, all of the pregnancy luteomas were unilateral in our series; the literature mostly refers to bilateral cases.2 Of note, in case 2, we were able to see large vessels around the mass, meaning that this particular pregnancy luteoma had an abundant blood supply.
The clinical setting and gross characteristics of patients may provide major clues to the diagnosis of pregnancy luteoma, although this is not always straightforward.2 It is puzzling that although earlier reports stated that this tumor-like lesion can vanish without treatment, in most cases, the authors of these reports performed partial ovariectomy or oophorectomy.1 We were unable to ascertain any further surgical detail from these reports. In 6 of our patients, the surgeons performed oophorocystectomy directly because the patients were being treated for a benign tumor. Case 2 was different; we performed an intraoperative freezing test. The results of this test indicated a “benign lesion, considering pregnancy luteoma”. However, we still performed the partial ovariectomy because the surgeon could not determine whether the lesion would return to normal spontaneously. However, an existing case report described a patient with an intestinal metastatic ovarian tumor that mimicked a pregnancy luteoma; this highlights the fact that conservative management should be recommended very carefully.22 Therefore, we believe that frozen biopsy is a better strategy during cesarean section for patients with suspected pregnancy luteoma.
Our study had several limitations that need to be considered. This was a retrospective study with a small number of patients; these cases were discovered incidentally. Consequently, there is a lack of systematic examinations, including imaging and androgen tests before and after surgery. Moreover, the specific details of surgery are incomplete.