Case
In January 2013, a 28-year-old primigravida
woman with sever lower abdominal pain presented to the emergency room of our hospital (Tehran Women General Hospital, Tehran,
Iran). She suffered from vaginal spotting and lower abdominal pain for 5-6 consecutive days.
She revealed a history of primary infertility
with 3 years duration. Because of clinical and
paraclinical manifestations of polycystic ovarian syndrome, metformin (1500 mg/day) has
been prescribed for induction of ovulation since
8 months ago. After starting this medication,
she developed regular menstruation pattern.
Her last menstrual period was 25 days prior to
admission date. She had no previous history of
pelvic inflammatory disease, abdominal surgery, abortion, or use of any intrauterine contraceptive device (IUCD). Her hysterosalpingography (HSG) demonstrated an otherwise
normal image without uteroovarian fistula. On
general examination, she was pale. Abdominal
examination showed abdominal distention and
guarding. On vaginal examination, the uterus
was normal in size and the cervix was tender
in motion. There was a tenderous mass in deep
palpation of right fornix. Clinical investigation
showed hematocrit level of 25.2%, and betahuman chorionic gonadotropin (β-hCG) titer of
3569 m IU/mL. Vaginal ultrasonography demonstrated empty uterus with 6 mm endometrial
thickness, free fluid in the peritoneal cavity,
and a right sided heterogeneous adnexal mass
(52×61 mm) beside the uterus. These findings
were suggestive of ruptured ectopic gestation.
Based on the above findings, the patient underwent emergency laparotomy in which demonstrated an enlarged and bluish right ovary with
a 4 cm hemorrhagic and ruptured ovarian mass
and a leaking hematoma on its surface. A 3×3
cm multicystic structure was identified in the
other side of right ovary and was presumed to
be a tumorous lesion. The uterus, both tubes
and the left ovary appeared to be normal in appearance. The right tube had normal fimbriated
end without dilation. There was no obvious
evidence of endometriosis, metastatic lesions,
pelvic inflammation, or adhesion. We found
1500 mL bloody fluid in abdominal cavity.
The diagnosis of ovarian pregnancy was made.
Therefore, surgical resection of hemorrhagic
mass with conservation of the right ovary was
done carefully. Because of bad looking appearance of the concurrent cyst in the right ovary,
ovarian cystectomy and endometrial curetting
were performed, respectively. The final pathologic analysis revealed vascularized chorionic
villi and trophoblastic cells within ovarian paranchymal tissue (Figes 1 , 2 ). Histopathological
study demonstrated that the excised cyst was
a benign serous cyst adenoma ( Fig 3 ). The endometrial sample showed decidual change, but
no gestational tissue. The post-operative course
was uneventful. On monitoring of β-hCG lev-
els, they were undetectable (<5 m IU/ mL) on
the 21 st
postoperative day. The patient menstru-
ated 37 days after the surgical operation.
Photomicrograph identified trophoblastic cells within
the ovarian parenchyma (H&E); ×200.
Photomicrograph identified chorionic villi (H&E);
×100.
Photomicrograph identified serous cyst adenoma
(H&E); ×400.
Discussion
Ovarian pregnancy is a rare variant of ectopic
pregnancy ( 1 - 4 ). This entity must be documented
by the four criteria of Spiegelberg: I. separation of
intact tubes from the ovaries, II. a gestational sac
occupying the normal position of the ovary, III. the
ovary and sac connected to the uterus by the uteroovarian ligament, and IV. ovarian tissue histologically demonstrated in the sac wall ( 16 ).
Its true incidence is underestimated. Some
of the suspected tubal pregnancies that are approached with conservative managements, without laparoscopic validation, are in fact ovarian
pregnancies ( 2 , 10 , 17 ). However, there is a rising in incidence of ovarian pregnancy in the last
decade, its true incidence is undetermined ( 3 , 10 ,
18 ). Furthermore, some studies suggested infer-
tility and the medications, which are prescribed
for ovulation induction, were associated with
an increased incidence of ovarian pregnancies
( 3 , 10 - 12 ). The suspected predisposing factors
were increased levels of estrogen and progesterone after ovulation induction ( 19 ). However, the
other reports did not support this hypothesis ( 2 ,
10 , 20 , 21 )
The exact etiologic factors of increased risk of
ovarian pregnancy after ART programs are unclear, but the most likely mechanisms are as follows: reverse migration of embryo after deep deposition, the use of large volumes of culture fluid
during embryo transfer (ET) procedures, difficult
ET, and tubal pathologies ( 12 , 22 - 24 ).
The risk of ovarian pregnancy in patients with
endometriosis or using IUCDs is controversial ( 3 ,
25 ). Unlike tubal pregnancy, the history of pelvic
inflammatory disease does not increase the risk of
ovarian pregnancy ( 2 , 20 , 21 , 26 ).
Preoperative diagnosis is a challenge to the clinician due to its rarity and lack of typical presenting
symptoms or documented risk factors ( 27 ). The
clinical findings are similar to tubal pregnancy or
hemorrhagic corpus luteal cyst ( 2 , 28 ). The most
complaints are abdominal pain and vaginal bleeding ( 3 , 10 ). The increased vascularity of the ovary
facilitates more massive bleeding and hypovalemic shock ( 3 , 18 ). The asymptomatic patients are
incidentally discovered during post- in vitro fertilization (IVF) monitoring ( 2 ). The ovarian pregnancies could be multiple gestations or heterotopic
type ( 2 , 29 ). There are very few recorded cases
in which ovarian pregnancy reached viability ( 30 ).
The ultrasound features are ovarian enlargement with or without containing a double hyperechogenic ring along with yolk sac, fetal part, or
fetal heart beat within ovary; fluid collection surrounding the ovary; and an empty uterus ( 2 , 4 , 20 ,
31 , 32 ). The sonographic differential diagnosis
between ovarian pregnancy and a ruptured corpus luteal cyst or a hemorrhagic ovarian tumor is
difficult ( 2 , 4 , 27 , 33 ). Although definite diagnosis is reached by laparoscopy or laparotomy, some
of ovarian pregnancies are identifiable by vaginal
ultrasound scanning ( 10 , 17 ). Ovarian pregnancies can be mistaken for hemorrhagic corpus luteal cysts or pregnancies in the distal part of tube
even at laparoscopy or laparotomy ( 3 ). Since pregnancy induced tissue destruction and lesser tissue
is available in conservative surgeries, postoperative diagnosis is also difficult ( 21 ). Therefore, the
physicians must exhibit a high degree of suspicion
for ovarian pregnancy when managing with pregnancy of unknown location.
In recent years, accurate and earlier diagnosis
has been performed by the application of vaginal
ultrasound scanning and quantitative hCG measurement ( 1 , 28 ). So, the management procedures
of ovarian pregnancy have evolved oopherectomy
by open surgical procedures and removal of gestational products or ovarian wedge resection by the
laparoscopy and/or medical management using intramuscular or local injection of chemotherapeutic
agents such as methotrexate (50 mg/m2) , hyperosmolar glucose, and prostaglandins, especially in
young patients who have an intact ovarian pregnancy and a desire for future childbearing ( 2 , 3 ,
10 , 17 , 20 , 29 , 34 - 36 ). Application of these modalities in management of ovarian pregnancy decreases
maternal mortality and morbidity rates ( 34 ).
Serous cyst adenoma is the most common benign epithelial cell tumor of ovary ( 5 ). In some
retrospective epidemiologic studies, an association has been demonstrated between prolonged
infertility/use of ovulation inducing drugs and an
increased incidence of ovarian epithelial cell dysplasia and cancer ( 13 - 15 , 37 - 40 ). The stimulation
of ovulation and increased levels of estrogen and
progesterone explain the potential suspected relationship between the use of fertility medications
and development of ovarian neoplasia ( 39 )
In the other hand, a high frequency of hyperplasia and metaplasia in the ovarian epithelial surface and 2.5-fold increased risk of ovarian cancer
have been showed in women with PCOS ( 41 , 42 ).
Although the contradictory data were reported in
the other studies ( 40 , 43 - 45 , 46 ), like in a study
by Brinton, the dosage and number of cycles of
ovulation-inducing drugs were not associated with
elevated risk ( 15 ). This difference is based on different study design, confusing factors such as duration and causes of infertility, parity, as well as
type and duration of medical therapy ( 33 ).
In some cohort studies, ovulation-inducing
drugs were related to an elevated risk of border
line serous tumors ( 13 , 40 , 47 ). However, there is
a possible association between prolonged use of
clomiphene citrate and invasive epithelial ovarian
tumors ( 40 ). This relationship should be pointed
out with caution. The confounding influence of infertility and nulliparity should be kept in mind. Additionally, the other authors did not confirm these
data in case-control studies ( 13 , 15 , 42 , 48 , 49 ).
Fertility experts frequently use metformin, an
insulin-sensitizing agent, as an ovulation-inducing
medication in PCOS ( 50 , 51 ). Although its connection with ectopic gestation is reported ( 52 ), its
association with serous cyst adenoma is undetermined. Some studies showed metformin use has
been associated with a significant decrease in risk
of prostate, pancreas, and breast cancer ( 53 , 54 );
however, its molecular effect on ovarian tissue,
and also, its effect on the risk of ovarian tumors
remain undetermined ( 50 ). Although superovulation and increased serum levels of ovarian steroid
hormones are the suspected pathogenesis of raising incidence of epithelial cell tumors following
induction ovulation, superovulation is very rare
event after metformin use ( 51 ); furthermore, estrdiol and progesterone serum levels are near the
physiologic levels in cycles after being induced by
this agent ( 50 ).
However, to the best of our knowledge, this
study is the first case report of coexistence of an
ovarian pregnancy and a serous cyst adenoma
in the same ovary following ovulation induction
with metformin. Review of the literature showed
only a few reports presenting the coincidence of
a serous cyst adenoma with an ectopic pregnancy.
They have been cases involving tubal or abdominal pregnancy coinciding with serous cyst adenoma ( 52 , 55 , 56 ). Vazquez et al. ( 55 ) reported tubal
pregnancy and ovarian serous cyst adenoma in a
40-year-old patient. The pregnancy was happened
after induction of ovulation by clomiphene citrate.
Pricop et al. ( 56 ) presented a case with abdominal
pregnancy and serous cyst adenoma. Werlin et al.
( 52 ) reported a coincidence of tubal pregnancy
with a serous cyst adenoma in the same fallopian
tube following induction ovulation with metformin, letrozol, and low-dose gonadotropin. After review of literature, we did not find original study
or documented case report about relationship between the use of metformin and ovarian tumors.
In our case, the presenting signs and symptoms
were severe abdominal pain with vaginal spotting,
elevated β-hCG, ovarian mass and empty uterus.
She fulfilled the criteria for ovarian pregnancy, as
by Spiegelberg’s outlines. She had a concurrent benign serous cyst adenoma in the same ovary. Our
patient was previously labeled with PCOS. Pregnancy happened following induction of ovulation
with metformin. In term of risk factors, infertility
and the use of ovulation inducing drugs might be
the possible predisposing factors for the ovarian
pregnancy. The relationship between metformin
and serous cyst adenoma is not clear.
Conclusions
Ovarian pregnancy is uncommon entity, which is difficult to diagnose. The microinvasive surgical
procedures and medical managements are effective therapeutic options in the treatment of unruptured ovarian pregnancies, especially in young patients. Although the current findings are not strong
to support a link between fertility drugs and ovarian cancer, it seems to be an association between
reduced fertility and increased neoplasia risk.
Careful inspection of the ovaries at surgery indicated the high risk of ovarian tumors for patients
with long-standing history of infertility or fertility
agents use in order to exclude the presence of a
neoplasm. Moreover, further prospective, multicenter, and long follow-up studies considering all
confounding factors are necessary to improve our
ability for diagnosis and treatment of ovarian pregnancy, and to determine the patho-physiological
mechanisms underlying the possible link between
infertility or the use of ovulation inducing drugs
and ovarian tumors.
Introduction
Ovarian pregnancy occurs when a fertilized
ovum implants in or on the ovary. This entity is
a rare variant of extrauterine pregnancy and represents 1.1-3% of all ectopic pregnancies or one
ovarian pregnancy per 7000-90000 live births ( 1 - 4 )
Serous cyst adenoma is a cystic ovarian tumor
containing serous fluid and solid- tissue component. This tumor is benign form, presenting as
cystic unilocular or multilocular ovarian mass with
thin wall and minimal papillary projections ( 5 ).
Polycystic ovarian syndrome (PCOS) is the most
common endocrinopathy among subfertile women
( 6 ). The most prominent presenting characteristics
are oligo/anovulation and hyperandrogenism ( 7 ).
Currently, metformin, an insulin-sensitizing agent,
was accepted as a favorable medication for ovulation induction in PCOS ( 8 , 9 ).
Infertility and subfertility managements including induction of ovulation seem to be responsible
causes in the occurrence of the ectopic pregnancies ( 10 - 12 ).
In some retrospective studies, an association has
been found between fertility drugs use and ovarian
neoplasia risk in infertile patients ( 13 - 15 ).
The case presented here is interesting in term of
the rarity of ovarian pregnancy and coincidence
with serous cyst ovarian tumor, and also occurring
after ovulation induction by metformin.