Keywords
lithopedion - stone baby - ectopic pregnancy - abdominal pregnancy - extrauterine
pregnancy
Palavras-chave
litopedia - bebê de pedra - gravidez ectópica - gravidez abdominal - gravidez extrauterina
Introduction
Ectopic pregnancy is the leading cause of pregnancy-related death during the first
trimester, and it is estimated to occur in 1 to 2% of pregnancies. Women who have
one ectopic pregnancy are at increased risk for another such pregnancy and for future
infertility.[1] Over 90% are located in the fallopian tube (interstitial: 2.4%; isthmic: 12.0%;
ampullary: 70.0%; and fimbrial: 11.1%), while the remainder get implanted in locations
such as the abdomen (1.3%), the ovaries (3.2%), cesarean scars (hysterotomy), and
the cervix.[2] Abdominal pregnancy refers to a pregnancy that has implanted in the peritoneal cavity,
external to the uterine cavity and fallopian tubes. The estimated incidence is 1 per
10,000 births and 1.4% of ectopic pregnancies.[3] There are reports of abdominal pregnancies occurring after hysterectomy.[4]
[5] Rarely, the fetus from an unrecognized abdominal pregnancy may die and calcify.
The resulting lithopedion (“stone baby”) may not be detected for decades, and may
cause a variety of complications (intra- abdominal abscesses, adhesions, masses, or
fistulas). In most cases, the lithopedion can be identified on a simple abdominal
x-ray of the abdomen, often as an incidental finding.[6] Given the rarity of implantation at these sites, much of the information surrounding
the diagnosis and treatment of these pregnancies has been derived from small observational
studies and case reports. This makes it so important to publish cases of ectopic pregnancies,
especially in such unusual presentations, so we may improve the optimal approach to
their evaluation and management, since it has been difficult to determine.
Case Report
We report the case of an elderly woman who was admitted to the emergency room of a
tertiary military hospital in the city of Rio de Janeiro, Brazil, with clinical symptoms
of intestinal obstruction. A 71-year-old woman, white, widowed, a retired telephone
operator, who was born and living in Rio de Janeiro, sought emergency care complaining
of abdominal pain in the hypogastric region and vomiting that had begun two days earlier.
She evolved with anorexia, abdominal distension, a cessation of flatus and bowel movements,
and fecal vomiting. She denied having had a fever before admission to the emergency
room. As pathological antecedents, she had systemic arterial hypertension, which was
controlled with regular use of medications. The patient underwent a reduction mammoplasty
at the age of 31, without other surgeries or comorbidities, and denied having any
allergies. She had her menarche at age 14, and menopause at 65, with regular cycles,
and was G5P1A3, with a gestation at 18 years of age completed with vaginal delivery.
The patient had 3 induced abortions, the last one at age 40. At 60 years of age, upon
routine transvaginal ultrasonography, a retained mummified fetus (abdominal pregnancy)
was diagnosed, and she was referred for surgical excision but did not accept it, because
she was completely asymptomatic.
Upon admission, the patient was alert, aware f time and space, with regular general
condition, dehydrated (2 + /4), and with normal skin color. She had arrhythmia, but
a normal heart rate, and a blood pressure of 200 × 100 mmHg. The patient was eupneic,
and had normal respiratory auscultation. The abdomen was globose, flaccid, hypertympanic
at percussion, and with weak peristalsis, with no signs of peritoneal irritation,
but discretely painful to superficial and deep palpation. There was a palpable mass
measuring ∼ 20 cm in its largest diameter, of hardened consistency and irregular contours,
adhered to deep planes, in the hypogastric region. There were no ascites or collateral
circulation. The rectal touch showed hardened stools in the rectal ampulla, with no
blood stains on the glove. The extremities of the patient exhibited no abnormalities.
Upon radiography, the acute abdomen routine showed a 20- × -15-cm radiopaque image
with organized bone density in the hypogastrium ([Fig. 1]). There was also significant distension of loops and air-fluid levels.
Fig. 1 Abdominal radiography showing a 20- × -15-cm radiopaque image with organized bone
density in the hypogastrium and, in addition, significant distension of the loops
and air-fluid levels.
The abdominal ultrasonography showed an image compatible with the retained fetus.
In addition, a computed tomography scan was suggestive of mesenteric ischemia. In
the emergency room, ∼ 700 mL of fecal fluid contents were removed through a nasogastric
tube, with concomitant volume replacement and analgesia. After the diagnosis of intestinal
obstruction, the patient underwent an exploratory laparotomy six hours after hospital
admission. The surgical inventory of the cavity confirmed the presence of a mummified
fetus in the pelvis ([Fig. 2]), as well as adherences of the pelvis at 60 and 80 cm from the ileocecal valve and,
at 10 cm from this location, an adherence between the ilium and the fetus. The small
intestine loops were distended, with violet color and without signs of ischemia; the
mesenteric vessels were palpable. The liver, the gallbladder and the common bile duct
did not present any macroscopic alterations. The uterus and right fallopian tube were
identified as being intact, without visualization of the left tube after surgical
excision of the fetus. A lysis of adhesions, dissection and resection of the mummified
fetus was performed, without complications, during the surgery. By the analysis of
the weight and size of the piece, along with the radiography performed, the fetus
was compatible with a term gestation ([Fig. 3]). The patient remained in the intensive care unit during the first three postoperative
days, breathing in ambient air. She presented right pneumothorax after deep vein puncture,
which was drained in water seal for four days. She developed satisfactory results,
being discharged eight days after surgery.
Fig. 2 Intraoperative view of the abdominal cavity showing the mass, including visible bone
structures, compatible with a mummified fetus (lithopedion) in the pelvis.
Fig. 3 Surgical specimen compatible with a “stone baby,” the product of a term abdominal
gestation.
Discussion
Atrash et al[3] demonstrated, from an analysis of 11 abdominal pregnancy-related deaths and an estimated
5,221 abdominal pregnancies in the United States, that there were 10.9 abdominal pregnancies
per 100,000 live births, and 9.2 abdominal pregnancies per 1,000 ectopic pregnancies.
The mortality rate was 5.1 per 1,000 cases of abdominal pregnancies. Only 1 out of
9 women who reached the hospital alive had an accurate preoperative diagnosis of abdominal
pregnancy, which suggests that preventing abdominal pregnancy-related death may depend,
at least in part, on increasing the awareness of physician awareness regarding its
clinical features.[3]
The potential sites of abdominal pregnancy include the omentum, the pelvic sidewall,
the broad the ligament, posterior cul-de-sac, the abdominal organs (the spleen, the
bowel, the liver, for example), large pelvic vessels, the diaphragm, and the uterine
serosa.[7]
[8]
[9]
[10]
[11]
[12]
It is not known whether abdominal pregnancies are a result of secondary implantation
from an aborted tubal pregnancy or the result of intraabdominal fertilization, with
primary implantation in the abdomen.[7]
[8] The risk factors for abdominal pregnancy include tubal damage, pelvic inflammatory
disease, endometriosis, assisted reproductive techniques, and multiparity.[10]
[13]
Because of the variable location in the abdomen, abdominal pregnancy is associated
with a wide range of signs and symptoms. In contrast to tubal ectopic pregnancies,
abdominal pregnancies may go undetected until an advanced gestational age; some pregnancies
go all the way to term. In such cases, the fetal movements can be detected and may
be painful, and the fetus may assume an unusual lie. When the pregnancy implants in
the bowel, nausea and vomiting may be prominent symptoms. Vaginal bleeding is less
frequent than in tubal ectopic pregnancies; however, vaginal bleeding may occur, since
the endometrium still responds to changes in pregnancy hormones.[14] Some women present with an acute abdomen and shock due to severe intra-abdominal
hemorrhage from placental separation or rupture of maternal blood vessels or viscera.
Bowel obstruction and formation of fistulae are other rare presentations.[3]
[14]
[15] In rare cases, the pregnancy may be diagnosed after a failed induction due to lack
of myometrial response to oxytocin stimulation.[16]
In order to make the diagnosis, all women of reproductive age with abdominal pain,
vaginal bleeding, or menstrual abnormalities should be tested for pregnancy. Once
pregnancy is established, the location of the pregnancy (intrauterine or extrauterine)
is typically made by ultrasound examination. A high index of suspicion is important
to establish a diagnosis of abdominal pregnancy. The classic ultrasound finding is
the absence of myometrial tissue between the maternal bladder and the placenta.[8]
[14] An empty uterus may be visualized. Other findings suggestive of the diagnosis include
poor definition of the placenta, oligohydramnios, and unusual fetal lie.[14]
An advanced abdominal gestation may be misinterpreted as being intrauterine if the
ultrasonographer does not evaluate the myometrium during the examination. Computed
tomography and magnetic resonance imaging scans can be useful to confirm the diagnosis,
distinguish anatomic relationships and potential vascular connections, and assess
placental adherence. The differential diagnosis includes ectopic pregnancy in other
locations, intrauterine pregnancy in a rudimentary uterine horn, abruptio placenta,
and uterine rupture.[17- 20]
Abdominal pregnancies, even when advanced, are interrupted at diagnosis, as the potential
for delivery of a healthy infant is poor, and the risk of maternal complications is
high. If the diagnosis is made late in the pregnancy, a viable infant may be delivered
via laparotomy. Expectant management to gain fetal maturity has been attempted, and
has been successful in a few cases.[21] Abdominal gestation implies a high incidence of fetal deformations and mortality,
as well as maternal mortality.[22]
The mainstay of the treatment for advanced abdominal pregnancy is surgery, but the
optimal approach has not yet been determined. The fetus can be delivered easily; the
key issue is how to manage the placenta. In this case, as it was a mummified fetus,
there were no concerns regarding the placenta or risk of bleeding related to it.
This type of ectopic pregnancy is very rare, and it occurs when the fetus from an
unrecognized abdominal pregnancy maybe dies and calcifies. The resulting lithopedion
(“stone baby”) may not be detected for decades, and may cause a variety of complications
(intra-abdominal abscess, adhesions, masses, or fistulas). Lithopedion is a rare event
that occurs in 0.0054% of all gestations. About 1.5 to 1.8% of the abdominal babies
develop into lithopedion. There are only ∼ 330 known cases of “stone babies” in the
world.[23]
In most cases, the lithopedion can be identified on a simple x-ray or on an ultrasound
of the abdomen, often as an incidental finding. What makes this case more interesting
is that the patient knew that she carried a mummified fetus and had probably been
warned about the risks. In this case, emergency surgery was performed due to intestinal
obstruction as a resultant complication.
