A rare case of an isolated primary hydatid cyst in the uterus in a 7-year-old child: Case report and review of the literature

Abstract

Introduction and significance

Hydatidosis is one of the diseases caused by tapeworms that infect humans during their life cycle and still pose a major problem.

A review of the medical literature has reported a few cases of serous cysts in the uterus.

In most cases, pelvic cysts are asymptomatic and may sometimes cause compressive symptoms or complications when ruptured.

Case presentation

We presented a case of a serous cyst of the uterus that was discovered through vague abdominal pain.

The definitive diagnosis of the case was made during surgery when the cyst was opened, where it was removed and the cavity was closed completely.

Clinical discussion

The diagnosis of a serous cyst is based on a good clinical history, with the help of serological tests, in addition to radiological investigations that help to determine the number of cysts, their location, and their surroundings, in order to choose the appropriate therapeutic intervention according to the size of the cyst and its location, for the best patient care.

Conclusion

Hydatid cysts of the uterus are rare, but they should be included in the differential diagnosis of pelvic cysts to avoid the accidental rupture of the cyst during surgery and the occurrence of an allergic reaction that can sometimes be fatal.

Highlights

• •Isolated primary hydatid cyst of the uterus is very rare.
• •Hydatid cysts are slow-growing, so they may remain asymptomatic for a long time.
• •The negative results of serological tests for a Hydatid cyst do not rule out its existence.
• •The treatment method for Hydatid cysts depends on the location and size of the lesion.

1. Introduction

Hydatidosis is a term used to describe the infection with a type of parasitic worm called Echinococcus granulosus, a type of tapeworm. It is estimated that there are about 2–3 million human cases in the world [1]. This disease is considered endemic in some parts of the world.

The lifespan of this worm is estimated to be between 5 and 20 months in most cases. Humans are one of the intermediate hosts during the life cycle of the worm, while dogs are the definitive host [2].

Humans can become infected with this disease either by consuming food contaminated with the eggs of this worm or by close contact with the definitive host [3].

When the eggs enter the human body, they penetrate the intestinal mucosa and spread to other organs. The liver is the most common site of infection, accounting for about 75 % [4]. However, uterine infection is very rare, estimated at about 0.3 % [5].

Hydatid cysts are usually asymptomatic, and most symptoms are due to complications, such as rupture of the cysts, which can cause allergic reactions.

These cysts can also damage the organs in which they are located.

The diagnosis is based on the clinical history, serological tests, and various imaging techniques.

This case is described in accordance with the criteria of SCARE [6].

2. Presentation of case

2.1. Patient information

We describe the case of a 7-year-old child living in a rural area who had been suffering from vague abdominal pain below the navel for two weeks, with nausea but no constipation, diarrhea, or bloody discharge. There were no associated urinary symptoms. The child had no history of contact with animals. She had been treated with an anticonvulsant before coming to us, without any external investigations prior to our review.

The family did not mention any family history of deformities or tumors.

2.2. Clinical findings

On examination, the child was in good general condition with a normal pulse and blood pressure and no fever.

On physical examination, the abdomen was soft without any obvious tender points with mild tenderness in the inguinal region. There were no signs of peritoneal irritation and no palpable masses were detected in the abdomen. The examination of the rest of the organs was within normal limits.

On examination of the genitalia, it was normal with no signs of vaginal obstruction.

A digital rectal examination was performed in conjunction with abdominal palpation, where a palpable mass was detected above the pubis between the fingers.

2.3. Diagnostic assessment

Laboratory examinations L revealed a hemoglobin of 12.8 g/dL, total white blood cell count of 11,000/mm³, platelet count of 324,000/mm.

All tumor markers, including carcinoembryonic antigen (CEA), CA 125, CA19-9, AFP, and B HCG were within normal ranges.

Abdominal ultrasound showed the presence of a pelvic cyst measuring 4 × 7 cm with a thickened wall and containing multiple septa, without the ability to identify its source.

The CT scan showed a cystic formation in the pelvis measuring approximately 8 × 7 cm, with thick walls, containing septa inside, located on the right side of the pelvis, causing compression of the bladder and pushing it to the left side of the pelvis. There were no other pathological formations in other parts of the body (Fig. 1.A-B).

Fig. 1.

A: CT/cross coronal view showing a cystic formation behind the bladder, compressing the bladder with a thick wall.

B: CT/cross axial view showing a cystic formation behind and to the right of the bladder, containing septa inside.

2.4. Therapeutic intervention

Based on the previous findings, it was decided to perform surgery.

Under general anesthesia, A transverse incision was made below and to the right of the umbilicus to the pelvis, where a cystic formation was found to be embedded in the muscular wall of the uterus with normal placement of the ovaries and fallopian tubes (Fig. 2.A).

Fig. 2.

A: Intraoperative image shows the hydatid cyst interpenetrating the uterine wall, where the green color indicates the hydatid cyst, the yellow color indicates the uterus, and the blue color indicates the right fallopian tube.

B: Intraoperative image shows the cavity of the cystic formation after opening it and removing the germenal membrane and emptying the fluid.

C: Gross appearance shows the germenal membrane of the hydatid cyst. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

It was decided to open the cystic formation, where a quantity of fluid came out with the germinal membrane characteristic of a hydatid cyst (Fig. 2.B-C). The cyst was completely excised with closure of the cyst cavity and thorough pelvic irrigation, and closure in layers.

Histopathologic examination shows hydatid cyst.

The child was monitored in the hospital for a week, then she was discharged in good general condition. She will continue taking the medication, albendazole, and will see us again in 3 weeks for liver enzyme testing.

3. Discussion

Hydatidosis is considered to be one of the most important diseases that humans can contract from animals [7].

This disease is widespread throughout the world, including the Mediterranean region, the Middle East, and others.

The main cause of this disease is a type of tapeworm called Echinococcus, which has four forms: E. granulosus, E. multilocularis, E. vogeli, and E. oligarthrus.

Hydatidosis is most commonly caused by the form E. granulosus, which grows at a slow rate of about 0.5 cm per year in the form of a chronic cystic lesion [8].

Dogs are the definitive host of this worm, where they grow inside the definitive host and release eggs that are excreted through the feces and ingested by the intermediate host, such as humans, cows, sheep, and others, through the consumption of food contaminated with these eggs or through close contact with the definitive host [3].

When these eggs reach the intermediate host's intestine, they hatch to produce larvae, which then penetrate the intestinal wall and enter the bloodstream [9].

The arrival of these larvae to the bloodstream means that they can migrate to different parts of the body, where the most common site of infection is the liver, followed by the lungs, while uterine infection is very rare [10].

The larvae form a chronic cystic lesion at the site of infection, which grows slowly each year. It is possible that the cysts may remain for a long time when the infection is outside the liver, until the cyst grows and presses on the organs or the cyst ruptures.

In most cases, pelvic hydatidosis is secondary to rupture of hepatic cysts during surgical resection or spontaneously. Pelvic infection is considered isolated only in the absence of other hydatid cysts in other parts of the body, such as the liver, lungs, peritoneal cavity, and others [11]. In our case, there were no other cysts in the body, and the cyst was isolated on the uterus. Therefore, this case is considered a primary infection in the pelvic cavity.

The clinical manifestations of hydatid cyst infection depend on the location of the cyst, its size, and its relationship to the surrounding organs [12]. Pelvic hydatid cysts may not show any specific symptoms for long periods of time, and may be discovered accidentally or by pressing on the surrounding organs.

The presence of cystic formation in the pelvis is considered a challenge in arriving at a diagnosis because the differential diagnosis for cystic lesions in the pelvis is wide and may include ovarian tumors, ovarian cysts, endometrial tumors, or leiomyomas and other [5].

The diagnosis of primary ovarian hydatid cyst is important due to the complications of this disease. It may cause urinary problems, or the cyst may rupture and cause an anaphylactic reaction. Secondary infections may also occur on the account of the cystic formation [13].

In the presence of a clinical suspicion of hydatid disease, serological tests may be helpful. Serological tests are useful in the initial diagnosis and follow-up after treatment, The detection of antibodies is more sensitive in the diagnosis of hydatid disease than the detection of antigen [14].

There are many serological tests, and ELISA is the most sensitive and specific among serological tests in the diagnosis of hydatid disease [15].

Negative serological test results do not exclude the diagnosis of hydatid disease, and there is no correlation between serological tests and the number or size of cysts (reference 49).

False-negative results are also possible, depending on the location of the lesion, the integrity of the cyst, and its ability to persist.

The likelihood of false-positive results increases in the presence of infection with other parasitic worms, cancer, and immune disorders.

In our case, we did not perform any of the serological tests because we did not put in our minds the diagnosis of the hydatid cyst before the surgical intervention.

Regarding radiological investigations, abdominal US can be the initial procedure.

Many reports suggest that computed tomography has a higher overall sensitivity than ultrasound (95 to 100 %) [16]. Computed tomography is the best way to determine the number, size, and anatomical location of cysts, and it is also better than ultrasound for detecting cysts outside the liver. Computed tomography can also be used to monitor lesions during treatment and detect recurrence of the disease [17].

Regarding percutaneous biopsy or aspiration, it can be used in the absence of positive serological tests.

In the case of liver cysts, this method is considered to have low rates of complications. However, this intervention is generally reserved for cases where other diagnostic methods are inconclusive due to the risk of secondary dissemination of cysts or anaphylaxis in case of cyst rupture [18].

Surgery is considered the gold standard for the treatment of hydatid cysts in the uterus, while the laparoscopic approach is controversial due to the increased risk of dissemination and high recurrence rate [19].

Exploration of the rest of the abdominal cavity is important to search for other cysts, especially hepatic.

Regarding drug therapy, it is considered to be very ineffective and is used in cases where there are contraindications to surgery, the cysts are located in multiple places, or in cases of incomplete resection, where Albendazole is given (400 mg/day; two 28-day cures 15 days apart) [20].

4. Conclusion

Hydatid cysts of the uterus are very rare and are often asymptomatic. They are diagnosed by radiological investigations. However, they should be included in the differential diagnosis of cystic lesions in the pelvis when facing any cystic formation in the pelvis, even in the absence of a history of contact with animals.

Abbreviations

US

ultrasound

CT

computed tomography

DRE

digital rectal examination

Consent of patient

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Provenance and peer review

Not commissioned, externally peer-reviewed.

Ethical approval

Not required for case reports. Single case reports are exempt from ethical approval.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author contribution

K.A: Conceptualization, resources, who wrote, original drafted, edited, visualized, validated, literature reviewed the manuscript, and the corresponding author who submitted the paper for publication.

K.S.: Supervision, visualization, validation, resources, and review of the manuscript.

Z.A, A.M and M.A.: Visualization, validation, and review of the manuscript.

H.D: MD, pediatrics surgery specialist, who performed and supervised the operation.

All authors read and approved the final manuscript.

Guarantor

Khaled Alomar.

Research registration number

N/A.

Conflict of interest statement

No conflicts of interest are present.

Data availability

The datasets generated during and/or analyzed during the current study are not publicly available because the Data were obtained from the hospital computer-based in-house system. Data are available from the corresponding author upon reasonable request.