Spontaneous perforation of the common bile duct (SPCBD) is an uncommon condition in adults [1,2]. Although the etiology remains uncertain, approximately 70% of cases are accompanied by choledocholithiasis [1,3]. Clinical symptoms vary widely, ranging from nonspecific signs such as abdominal pain and distension to severe manifestations, including peritonitis and shock [4]. This variability in symptoms complicates the diagnosis of SPCBD. However, because SPCBD is associated with poor prognosis and high mortality, early suspicion and prompt diagnosis are essential [3].

This report presents a case of SPCBD diagnosed in a patient who presented with nonspecific abdominal pain and fever.

A 73-year-old male presented to the outpatient gastroenterology clinic with a 2-day history of right upper quadrant abdominal pain and fever. The pain, initially localized to the right upper quadrant, gradually spread across the entire abdomen.

The patient had a history of coronary artery occlusive disease, for which coronary stent implantation had been performed. Aside from this, there was no history of other chronic medical conditions, gallstones, trauma, prior abdominal surgeries, or congenital anomalies. He reported social alcohol consumption and denied any other significant social or family history.

At the time of admission, the patient’s vital signs were as follows: blood pressure, 154/82 mmHg; pulse rate, 77 beats per minute; respiratory rate, 16 breaths per minute; and body temperature, 36.0°C. On physical examination, there was no abdominal tenderness or evidence of jaundice.

Laboratory tests performed at the clinic revealed white blood cell count of 15,820/uL, hemoglobin of 14.1 g/dL, and platelet count of 177,000/uL; serum aspartate aminotransferase 15 IU/L, alanine aminotransferase 10 IU/L, alkaline phosphatase 76 IU/L, total bilirubin 1.87 mg/dL, direct bilirubin 0.47 mg/dL, gamma-glutamyl transferase 53 IU/L, amylase 25 U/L, and lipase 11 U/L. C-reactive protein was elevated at 21.52 mg/dL. The tumor markers were unremarkable, with carbohydrate antigen 19-9 measured at <2 U/mL and carcinoembryonic antigen at 1.9 ng/mL.

Abdominal computed tomography revealed dilation of the common bile duct with wall thickening, and a 3.5 cm hypodense lesion was identified around the common bile duct within the pancreas. The gallbladder was collapsed with diffuse wall thickening, but there was no evidence of perforation or acute cholecystitis. And there was mild dilatation of the intrahepatic bile ducts (Fig. 1).

Magnetic resonance cholangiopancreatography further demonstrated a 3.5 cm hypodense lesion on the right lateral aspect of the intrapancreatic common bile duct, with suspicion of perforation or extrusion. T2-weighted imaging showed multiple low signal intensity lesions within the hypodense area (Fig. 2).

Given these findings, SPCBD related to choledocholithiasis was suspected. Due to the high risk associated with emergency surgery, percutaneous transhepatic biliary drainage was initially attempted but was unsuccessful. Surgical intervention was undertaken. Due to severe inflammation and adhesions around the common bile duct, pylorus-preserving pancreaticoduodenectomy was performed.

Histopathological examination revealed acute and chronic cholangitis with perforation and periductal fibrosis, abscess formation extending into the pancreatic parenchyma and peripancreatic fat, and reactive hyperplasia in peripancreatic lymph nodes (Fig. 3).

The patient’s condition improved following antibiotic treatment for intra-abdominal infection and is currently under outpatient follow-up.

SPCBD is a potentially fatal condition, underscoring the importance of prompt diagnosis [3]. However, the extreme rarity and nonspecific clinical presentation of SPCBD create significant challenges in differential diagnosis [3,5]. Therefore, in patients presenting with abdominal symptoms who undergo abdominal ultrasound or computed tomography, findings such as bile duct defects, peribiliary ascites, peritonitis, fluid collections, or abscesses should raise suspicion for spontaneous bile duct perforation [4]. Diagnostic tools that assist in establishing a differential diagnosis include hepatobiliary scintigraphy and endoscopic retrograde cholangiopancreatography (ERCP), which can confirm bile leakage, as well as magnetic resonance cholangiopancreatography, which can identify structural defects [6].

Treatment options for spontaneous bile duct perforation range from invasive interventions to surgical approaches. Conventional treatment has primarily involved exploratory laparotomy with peritoneal drainage and bile duct decompression [5,7]. In cases of intractable distal obstruction, persistent fistula, or bile duct leakage, more invasive surgical options, such as Roux-en-Y choledochojejunostomy, may be considered [8]. However, recent reports have documented cases in which stent placement via ERCP and percutaneous drainage-approaches similar to those used for iatrogenic bile duct injury-have been attempted for spontaneous bile duct perforation [1,9]. In Korea, Yoo et al. [10] managed a case of spontaneous bile duct perforation using endoscopic sphincterotomy and endoscopic nasobiliary drainage, while Yang et al. [3] reported effective management of a case unresponsive to percutaneous drainage by utilizing a fully covered self-expandable metallic stent. Thus, in stable patients or those with localized lesions, ERCP-guided stent placement may serve as an efficient alternative [1,9].

Unlike other cases of SPCBD, this case involved a perforation in the intrapancreatic portion of the common bile duct, with bile leakage confined to the pancreas. Consequently, there were no signs of peritoneal irritation from bile leakage, nor were there typical symptoms such as jaundice, making bile duct perforation challenging to suspect. Initial computed tomography facilitated detection by revealing a loss of continuity in the bile duct wall. However, due to extensive adhesions and the presence of a pancreatic abscess around the perforation site, clinical improvement was unlikely to be achieved with localized stent placement via ERCP or endoscopic ultrasound-guided drainage alone. Furthermore, percutaneous transhepatic biliary drainage, which was attempted for preoperative biliary decompression, was unsuccessful as the intrahepatic bile ducts were not sufficiently dilated to allow the procedure. As previously mentioned, the extensive adhesions and associated peritonitis rendered conventional surgical repair or T-tube drainage insufficient for definitive management. Therefore, a pylorus-preserving pancreaticoduodenectomy was performed as the most appropriate surgical approach.

SPCBD, as demonstrated in the reported case, remains a condition with considerable challenges in both diagnosis and management. No established standard treatment protocol exists, and treatment strategies may vary according to the patient’s clinical presentation. Thus, further accumulation of case studies and clinical experience is essential to establish effective diagnostic and therapeutic approaches.