Biloma is an encapsulated collection of bile that can occur outside or inside the biliary system within the abdominal cavity. It is a rare condition with an incidence of 0.3%–2% [1]. Mean time for developing post-cholecystectomy biloma is about 2 weeks from the surgery, but in the literature, cases up to 5 years from the surgery have been reported. In rare cases, biloma can present on postoperative day 5–15 and infrequently, past 1 year [4,7]. In this study, the patient presented with complaints of a painful lump in the upper abdomen and no jaundice two months after laparoscopic cholecystectomy.

Post laparoscopic biloma cysts have not been reported before. Biloma most commonly occurs as free fluid in the abdominal cavity but not collected in a cyst. Biloma as a complication of laparoscopic cholecystectomy can be the result of the leakage from an inadequately secured cystic duct stump of an accessory right hepatic duct, cystic duct, duct of Luschka in the gallbladder fossa of the liver or injury to the main biliary ducts [1,8,9]. We found the very rare case that biloma collected in an isolated cyst at the epigastric area. The risk of injury of CBD increases if the cystic duct has similar size with CBD which can lead to misidentification. In our case, we had doubts about the assessment of the cystic duct and CBD, so we decided to dissect the serous layer of the CBD to ensure the junction of the cystic duct and CBD. This procedure made ischemia and micro perforation to the serous layer of CBD and caused further bile leaking and collecting in the capsulated mass resulting in a rare biloma cyst. Intra operative cholangiography (IOC) was recommended to confirm the structure of the cystic duct and CBD.

Our patient underwent MRCP that found a large epigastric cystic mass full of leaking bile, without any signs of CBD injury. Abdominal imaging, such as abdominal ultrasound (US), multi-slice computed tomography (MSCT), magnetic resonance cholangiopancreatography (MRCP), and Chole-scintigraphy using 99mTc hepatobiliary iminodiacetic acid (HIDA) scan, are crucial to identify biloma and rule out other possible etiologies [10]. Ultrasound (US) is preferable as the first-level imaging method, since it is non-invasive, fast and easy to perform. US findings suggest biloma are a hypo-anechoic fluid collection, with well-defined margins, sometimes encapsulated, mono- or pluriconcamerate appearance, in a typical location (right upper abdominal quadrant: sub- or intrahepatic, below the diaphragm) and no vascularity on color Doppler US. The size of a biloma may vary from a few centimeters up to 40 cm in diameter. But the sensitivity of abdominal US is low (70%), though it is used as the initial imaging in the evaluation of biloma. The sensitivity and specificity of CT scan are approximately 90% and those of MRI are above 95% in the detection of biloma and bile leak; however, smaller bilomas can be missed [4,10]. The MRCP sequences are helpful to identify the source of the biliary leak. Specifically, thin-slab MRCP sequences may show the point of communication between the fluid collection and bile ducts. Thin-slab MRCP sequences are also helpful in depicting the detailed anatomy of the biliary system and in detecting accessory biliary ducts, which could potentially be the source of the bile leak [9,11].

In this report, we performed percutaneous drainage with 5 mm laparoscopic trocar and 16 Fr NGT for drainage with local anesthesia which could be done in the outpatient clinic, and the patient was discharged on the same day with the tube connected to a collecting bag. Observation was done every week to evaluate the drain product, for any sign of infection and to measure size of lump. Treatment of biloma depends on the severity of the disease. Asymptomatic patients with small sized biloma can be managed conservatively. Open surgery is not the initial treatment nowadays, because there are many other treatment options. Open surgery is often chosen for diffuse biloma with persistent leakage or with underlying disease to secure the effectiveness of bile drainage and control intraabdominal infection. Most postoperative bilomas are managed by percutaneous drainage with the placement of stent endoscopically. If the drainage and conservative treatment with broad-spectrum antibiotic therapy fail, the advanced management with stent placement for prolonged drainage, micro-coil, and ethanol intrahepatic embolization would be the treatment options [1,3].

Our patient after 2 months follow-up has no complaints, and when the abdominal lump was gone, then tube could be removed. The patient was evaluated with MSCT showing the biloma was diminished with favorable outcome from the percutaneous drainage. The solution to resolving this complication is early diagnosis and percutaneous drainage under CT guidance. The current body of knowledge is still small, and further research is required to recognize risk factors and prevent future biloma occurrence, reducing morbidity and mortality of the patients.