Introduction

Liver cysts can be found as alone, numerous, or disperse, especially in cases of polycystic liver disease [1]. Simple cysts are found in about 5 to 10 percent of people, and their occurrence increases significantly as people get older. Polycystic liver disorder is a genetic condition with an autosomal dominant pattern [2, 3]. Mutations in PRKCSH and SEC63 encoding β subunit of glucosidase II and Sec63, respectively, trigger it [4]. Both proteins play a role in the molecular machinery that helps with the translocation, folding, and quality control of newly synthesized glycoproteins in the endoplasmic reticulum [5]. Neoplastic cysts, including benign biliary cystadenocarcinomas and biliary cystadenomas, are acquired, but the exact cause remains unknown [5]. Traumatic cysts are formed when there is bile leakage from a damaged intrahepatic bile duct following an injury [6].

Most liver cysts don’t show any symptoms. Sometimes they can be detected as a mass during a physical exam [6]. Most of them are discovered incidentally during abdominal imaging, particularly with ultrasound [6]. Approximately five percent of patients show symptoms and report vague issues like pain, nausea, feeling full quickly, vomiting, or heartburn [6]. After identifying a cyst, it’s important to differentiate a simple cyst from other types of cystic lesions in the liver, such as cystic neoplasms and hydatid cysts. Some complications of liver cysts that have been reported include torsion, biliary fistula, obstructive jaundice, intracystic hemorrhage, rupture, infection, malignancy, portal vein occlusion, portal hypertension, varices, and Budd-Chiari Syndrome [7—9].

A rare but noteworthy complication is the formation of a fistula between a liver cyst and the abdominal wall [10]. This abnormal complication can result from infection or trauma to the cyst, leading to erosion and fistulous tract development [11]. Such a fistula is not only a complication of the clinical picture, but it also presents a diagnostic and therapeutic problem [11]. Optimizing patient outcomes requires an understanding of the pathophysiology, presentation, and management of this unusual complication [12].

This report describes the clinical and pathological aspects of a simple liver cyst complicated by a fistula into the abdominal wall, discussing its diagnostic and treatment dilemmas according to the existing literature.

Case presentation

A 29-year-old male presented to Madinat Zayed Hospital in April 2024 with left pneumonia, which was treated successfully with intravenous antibiotics. The patient was obese, with a BMI of 30.56, and has a past medical history of appendectomy performed 10 years ago. A CT scan of the chest, abdomen and pelvis performed on April 19, 2024, revealed patchy consolidation with air bronchograms and bronchiectasis in the medial basal segment of the left lower lung lobe, accompanied by ground-glass opacities in a tree-in-bud pattern across the remaining segments of the left lower lung lobe, suggesting an infective etiology.

Additionally, the scan identified an 11×10×5 cm well-delineated hypodense lesion, inseparable from the lateral aspect of the right hepatic lobe. The lesion showed partial marginal calcification with no significant contrast enhancement and no signs of infiltration into the liver or adjacent structures. Differential diagnoses included a partially calcified hydatid cyst and neoplastic lesions like biliary cystadenoma, necessitating further evaluation and histopathological correlation.

Laboratory investigations revealed a negative hepatitis screen, AFP of 1.2 IU/ml (normal), CEA of 1.32 mcg/L (normal), CA19-9 of 51.7 units/ml (elevated), and echinococcosis antibodies<1:160 (normal). Based on the clinical and radiological findings, laparoscopic deroofing of the liver cyst was performed on May 17, 2024. Operative findings indicated that the right lobe of the liver was adhered to the abdominal wall. A cyst, measuring approximately 15×15 cm, was identified and attached to the liver. Aspiration yielded 400 ml of pure bile. The cyst was opened, and part of its wall was excised and sent for histopathology. A small opening measuring about 0.5 cm was observed on the liver surface at the point of attachment, surrounded by hard fibrosis. Minimal bile leakage was noted, which was managed with TachoSil gauze and Gluetac application to seal the opening. A 14 Fr drain was placed in the cyst.

Post-operatively, the patient recovered well. The abdominal drain was removed on postoperative day three, and the patient was discharged in good condition. During follow-up on day 11, the patient was seen in the outpatient clinic, reported doing well, and had his sutures removed. The histopathological examination of the cyst wall confirmed a benign cystic lesion with a single layer of columnar epithelium, fibrous wall, chronic inflammation, and hemorrhage. No ovarian-type stroma, dysplasia, or malignancy was identified. The lining cells were positive for CK19 and CK7 and negative for Calretinin and WT-1, favoring the diagnosis of a simple biliary cyst.

Fig. 1. Abdominal CT scan showing 11×10×5 cm liver cyst in right lobe.

Fig. 2. Abdominal CT scan showing liver cyst in right lobe with calcification.

Fig. 3. Abdominal CT scan showing 11×10×5 cm liver cyst in right lobe.

Fig. 4. CT scan coronal view of liver cyst in right lobe.

Fig. 5. CT scan coronal view of liver cyst in right lobe.

Fig. 6. CT scan sagittal view of liver cyst in right lobe.

Fig. 7. CT scan sagittal view of liver cyst in right lobe.

Fig. 8. Abdominal wall bulge (cyst) attached to right hepatic lobe, aspiration done and 400 ml bile was drained.

Fig. 9. Abdominal wall bulge (cyst) attached to right hepatic lobe, aspiration done and 400 ml bile was drained.

Fig. 10. After De-roofing of cyst, the fistula opening at right hepatic lobe.

Discussion

This case report presents a case of a 29-year-old male who was admitted with acute left-sided pneumonia for which he received intravenous antibiotics. Further imaging demonstrated an approximately 11×10×5 cm sized, predominantly hypodense mass in the right hepatic lobe with only a small area of marginal calcification and minimal contrast enhancement. Serum CA19-9 levels were raised, whereas other tumor markers were not significantly increased. Laparoscopic deroofing of the cyst revealed a 15×15 cm cyst in close contact with the liver and the abdominal wall filled with bile, measuring 400 ml. A histopathological examination of the lesion established the diagnosis of benign biliary cyst. The patient had an uncomplicated postoperative course and was well on follow-up.

Simple hepatic cysts are usually non-cancerous and do not cause symptoms; the patient may be diagnosed accidentally during other imaging tests [6]. However, the complications include infection, rupture, hemorrhage, or compression of other structures in the surrounding area [11]. The formation of a fistula between the hepatic cyst and the abdominal wall is rather a rare occurrence. The majority of hepato-cutaneous fistulas have been described in association with hydatid disease or pyogenic liver abscesses [13]. For example, a case report documented a hepato-cutaneous fistula due to an E. coli-induced pyogenic liver abscess treated with antibiotics and saline lavage only [14]. On the other hand, our case was a simple biliary cyst with fistulous communication to the abdominal wall, a presentation rarely reported in the literature. Bile within the cyst and adhesion of the cyst to the abdominal wall indicate that the cyst communicates with the bile duct and the outside areas [15]. This condition required surgical management and laparoscopic deroofing to excise the cyst and treat the fistulous complication.

Abdominal computed tomography, ultrasonography (U/S), magnetic resonance cholangiopancreatography, and endoscopic retrograde cholangiopancreatography are really helpful for diagnosing the abdominal fistulas and cystic situation [16]. The primary diagnostic tools that we usually go for are CT scans and ultrasounds, which can be used in any situation [6]. ERCP is one of the more invasive tools that can give clear detection and treatment options, such as sphincterotomy for patients with intrabiliary cyst ruptures. Meanwhile, MRCP is used to determine where the obstruction of the biliary system is located(17, 18). In our case report, findings of the CT scan identified an 11×10×5 cm well-delineated hypodense lesion, inseparable from the lateral aspect of the right hepatic lobe. The lesion showed partial marginal calcification with no significant contrast enhancement and no signs of infiltration into the liver or adjacent structures.

Patients with hepatic cysts have been reported to have raised serum CA19-9 level, both benign and malignant [19]. In our case, the elevated CA19-9 level had returned to normal postoperatively, as reported by other authors. For instance, a case report described a ruptured large hepatic cyst with increased serum CA19-9 concentrations that reduced following laparoscopic fenestration [10]. This implies that the elevated CA19-9 levels in benign hepatic cysts may be due to irritation or inflammation of the cyst wall and not neoplastic transformation.

Conclusion

Indeed, this case demonstrates that, although simple hepatic cysts are benign lesions, it is necessary to consider less frequent but serious complications, including abdominal wall fistulas. It also underscores the need for detailed diagnostic work-up and radiologic and laboratory investigations to enable the correct management plans. Laparoscopic deroofing was successful in the treatment, therefore the patient had a good outcome.