Primary giant hydatid cyst of the retroperitoneum: Diagnosis and therapeutic approaches

Abstract

Introduction and importance

Primary hydatid cyst of the retroperitoneum is an exceedingly rare manifestation of hydatid disease. Diagnosis proves challenging due to nonspecific symptoms, and the condition is typically not suspected when facing a retroperitoneal cystic mass, necessitating awareness among clinicians and surgeons, particularly in endemic regions.

Case presentation

A 45-year-old male with a three-month history of progressive abdominal enlargement and pain. Living in a rural area, he exhibited a 30 cm, well-defined retroperitoneal cyst, with no guarding confirmed by CT-scan, with characteristic daughter cysts. The diagnosis of primary retroperitoneal hydatid cyst was supported by positive hydatid serology and eosinophilia. Surgical intervention was crucial, and a complete pericystectomy, with 4 cm of pericyst on the aorta due to safety concerns, was performed after three months of preoperative albendazole-based treatment. The postoperative course was uneventful, and a two-year follow-up revealed no recurrence.

Clinical discussion

The prevalence of hydatid disease in North Africa is high, yet retroperitoneal cases are rare. The difficulty to diagnosis retroperitoneal masses, underscores the importance of precise patient evaluation and detailed imaging analysis. Percutaneous puncture is contraindicated due to the risk of dissemination, highlighting even more the significance of accurate preoperative diagnosis. Surgery, coupled with Albendazole treatment, remains the gold-standard, associated with meticulous intraoperative precautions to prevent disease dissemination.

Conclusion

Primary retroperitoneal hydatid cyst is rare. Diagnosis is difficult. Precise determination of patient's background and detailed analysis of imaging findings are mandatory. Percutaneous puncture is forbidden as it leads to disease spreading or even anaphylactic shock. Surgical excision is the gold-standard.

Highlights

• •Primary retroperitoneal hydatid cyst are rare, emphasizing its infrequent occurrence in the natural course of hydatid disease.
• •This rarity poses challenges in diagnosis and necessitates awareness among clinicians and surgeons.
• •Diagnosing primary retroperitoneal hydatid cyst is difficult especially when encountering a retroperitoneal cystic mass, making accurate diagnosis challenging.
• •The patient's rural residence, contact with animals, and specific imaging findings played crucial roles in indicating the possibility of a hydatid cyst.
• •Surgery coupled with preoperative Albendazole-based treatment, is the primary treatment with successful outcome along with no recurrence.

1. Introduction

Primary hydatid cyst of the retroperitoneum is a very rare condition that may occur in the natural history of hydatid disease [1]. Diagnosis is difficult as symptoms aren't specific [2] and primary retroperitoneal hydatid cyst is usually not suspected when facing a retroperitoneal cystic mass [3]. However, clinicians and surgeons must be aware of this condition, especially in an endemic area.

This case report has been reported in line with the SCARE Criteria [4].

2. Case report

A 45-year-old male presented with a progressive increase in abdominal circumference evolving for three months. He had no past medical or surgical history. He was living in a rural area. The patient complained of abdominal pain and heaviness. He didn't mention any fever, jaundice or weight loss. Physical examination found a 30 cm well-defined, slightly mobile and dense mass extended from the left upper quadrant to the pelvis with no guarding. Laboratory findings were normal except eosinophilia of 14 %. Hydatid serology was positive. CT-scan revealed a giant retroperitoneal cystic mass of 30 cm (Fig. 1).

Fig. 1.

Computed tomography: Retroperitoneal cystic mass measuring 30 cm with mass effect. White star: daughter cyst. White arrow: Left kidney. Red arrow: Aorta. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

The lesion exhibited well-defined borders without contrast enhancement, displaying a characteristic image consistent with daughter cysts. It exerted a notable mass effect on the neighbouring organs, particularly impacting the left kidney and the aorta.

The diagnosis of primary retroperitoneal hydatic cyst was retained and the patient was put on a preoperative albendazole-based treatment for three months. Surgery was performed through a mid-line laparotomy. Thirty litres of hydatid material including daughter vesicles were aspirated from the cyst after its isolation from the rest of the abdominal cavity (Fig. 2). A complete pericystectomy was then performed, leaving only 4 cm of pericyst on the aorta, as dissection was dangerous. Postoperative course was uneventful. Tha patient was put on Albendazole for another three months. After a two-year follow up including physical examination, ultrasound and hydatid serology every 6 months.

Fig. 2.

Peroperative view: Cyst puncture after its isolation from the rest of the abdominal cavity. Red arrow: daughter vesicles. White arrow: pericyst. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

The patient didn't experience any recurrence.

3. Discussion

Hydatid disease is a public health concern in North Africa, particularly in Tunisia, where it is mainly caused by Echinococcus granulosus. This zoonotic disorder can affect various organs, leading to diverse complications. While the spleen, kidneys, and pancreas are less commonly involved, hydatid disease in the retroperitoneum, as observed in our case, is rare. Many cases may remain asymptomatic for extended periods, with symptoms varying based on cyst location, number, and size. [5,6]

Presenting as a retroperitoneal cystic mass, it is often confused with lymphangioma, pseudomyxoma retroperitoneal or sarcoma [3,7]. As a result, clinicians and surgeons usually don't suspect the hydatic origin of the mass leading to wrong diagnosis and inadequate treatment. Thus, precise determination of patient's habits, origin and living conditions are mandatory. Detailed analysis of the imaging findings is compulsory. Ultrasound should be the first test to request in front of a hepatic mass unfortunately the patient was admitted from another hospital with the initial CT scan, emphasizing that even in an endemic country like ours, retroperitoneal localization is rare in routine practice.

In our patient, several clinical indicators strongly pointed towards the presence of a hydatid cyst. Firstly, the patient's epidemiological profile is notable, originating from an endemic region, residing in a rural environment, and having regular contact with sheep and dogs. Secondly, the identification of daughter cysts on the CT scan is highly indicative of hydatid disease [8]. Lastly, elevated eosinophil count and positive hydatid serology served to confirm the diagnosis.

Concerning the treatment, percutaneous puncture is forbidden as it leads to disease spreading or even anaphylactic shock emphasizing the importance of a preoperative diagnosis when it comes to retroperitoneal cyst.

Perioperative Albendazole-based treatment may decrease the risk of recurrence [9,10]. We used Albendazole 3 months prior to surgery and another 3 month after surgery we monitor blood cell count and hepatic enzymes every 2 weeks during the medical treatment. In fact albendazole may cause bone marrow suppression and increases the risk of hepatotoxicity, stressing the value of monitoring.

Surgery remains the gold-standard treatment [11]. Preventing peroperative dissemination of hydatid material is crucial, by isolating the cyst from the rest of the abdominal cavity using gauze swabs soaked by scolicidal solution. In our case we performed a complete pericystectomy, leaving only 4 cm of pericyst on the aorta to prevent major vascular injury especially in a benign pathology among relatively young patients.

After two years now to follow up the patient is satisfied with the treatment, and showed no signs of relapse.

4. Conclusion

Primary retroperitoneal hydatid cyst is rare. The diagnosis is difficult. A precise determination of patient's background and detailed analysis of imaging findings are mandatory. Percutaneous puncture is forbidden as it leads to disease spreading or even anaphylactic shock. Surgical excision is the gold-standard therapy.

Consent

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

Ethical approval

Our institutions “la Rabta Hospital” and “School of Medicine of Tunis” require no ethical approval for case series. It is required for studies on human participants. This is just a case series with written patient approval.

Funding

None.

Author contribution

Amine Sebai: conceptualization, data curation, redaction, project manager

Elaifia Rany: conceptualization, data curation, redaction, project manager

Souhaib Atri: conceptualization, redaction

Ahmed Ben Mahmoud: resources, visualization

Haddad Anis: resources, visualization

Montassar Kacem: supervision, validation, visualization

Guarantor

Elaifia Rany.

Research registration number

Not applicable.

Conflict of interest statement

None.