Gallbladder agenesis diagnosed during pregnancy- Case report and a literature review

Abstract

Introduction and importance

Gallbladder agenesis (GA) is a rare congenital anomaly. It results from failure of the formation of gallbladder primordium from the bile duct. This cohort of patients can present with symptoms of biliary colic and get misdiagnosed as cholecystitis or cholelithiasis.

Case presentation

Here we discuss a case of gallbladder agenesis presenting with symptoms of typical biliary colics in a 31 year old female patient during her second pregnancy. She underwent two ultrasound scans (USS) which couldn't visualise a gallbladder. She eventually had a magnetic resonance cholangiopancreatography (MRCP) which confirmed the absence of a gallbladder.

Clinical discussion

Diagnosis of gallbladder agenesis in adult life poses a diagnostic dilemma. This is partly due to misinterpretation of USS results. Still, some patients get diagnosed with this condition during attempted laparoscopic cholecystectomy. However, with a thorough understanding of the condition, unnecessary surgeries can be prevented.

Conclusion

Misdiagnosis is possible and can lead to unnecessary surgeries. Appropriate and timely investigations can diagnose GA. One should have high index of suspicion when an USS result shows a non-visualisation of the gallbladder, contracted or a shrunken gallbladder. It is prudent to further investigate this cohort of patients to rule out gallbladder agenesis.

Highlights

• •Gallbladder agenesis is a rare congenital anomaly.
• •Initial investigation with USS can provide misleading information. This could lead to inaccurate diagnosis.
• •MRCP can be diagnostic of gallbladder agenesis in most of the settings.
• •Appropriate investigations could avoid unnecessary surgery in the case of gallbladder agenesis.

1. Introduction

Agenesis of the gallbladder is a rare congenital anomaly. During embryological development, the liver bud originates from the distal part of the foregut in the fourth week of gestation. The connection between developing liver parenchyma and the foregut forms the precursor to the future bile duct. The gallbladder primordium arises from the caudal aspect of this bile duct as an outgrowth. This occurs between the 4th and 5th weeks of gestation [1]. Failure to do so can result in gall bladder agenesis [2].

Diagnosis of gallbladder agenesis in adult life poses a diagnostic dilemma due to multiple reasons. Clinical presentation of these patients can mimic biliary disease [3]. Predominant symptoms include biliary colic, dyspepsia and jaundice [4]. This cohort of patients gets investigated initially with an ultrasound scan (USS) to look for a biliary pathology. However, the USS could misinterpret GA as a fibrotic gallbladder or a shrunken gallbladder [5]^, [6], which can lead to inaccurate diagnoses such as chronic cholecystitis or cholelithiasis, resulting in unnecessary surgical procedures [7]^, [8]^, [9]. The majority of the cases reported in the literature were diagnosed intraoperatively [10]. This highlights the need for proper preoperative investigations to confirm the diagnosis of GA and avoid unnecessary surgeries and surgical complications.

This case report has been reported in line with the SCARE criteria [11].

2. Presentation of case

A 31 years old pregnant female presented to the emergency department with intermittent right upper quadrant pain. She was 17 weeks and five days pregnant with her second baby. She experienced on and off right upper quadrant pain throughout the pregnancy. This episode was going on for three days intermittently, however was constant at the time of presentation. The episode was associated with vomiting and the pain was aggravated by food. She was otherwise healthy other than being diagnosed with migraine and was not on any regular medications. Her surgical history included a laparoscopic appendectomy three years back. She denied any family history of gallbladder agenesis. Her first pregnancy was complicated with gestational diabetes, however, denied any right upper quadrant pain. She was allergic to morphine, codeine, tramadol and penicillin. She's a non-smoker and denied any ethanol consumption.

On examination, her vitals were stable and apyrexic. She was tender in the right upper quadrant. Abdomen was soft with no peritonism. Her blood tests were unremarkable with normal white cell count, C-reactive protein, liver function tests (bilirubin, alanine transaminase, alkaline phosphatase, and gamma-glutamyl transferase) and lipase. At this stage our tentative diagnosis was a biliary pathology. An inpatient USS was arranged to further assess her. The USS didn't visualise a gallbladder. However exquisite right upper quadrant tenderness was demonstrated during the USS. Common bile duct (CBD) was normal in diameter measuring 4 mm and liver looked normal. Obstetric scan showed single uterine pregnancy appropriately grown for age. A target USS was repeated the next day attempting to localise the gallbladder, however the gallbladder was not definitely visualised again after an appropriate period of fasting. Possible diagnosis of GA was suspected at this stage. She was discharged home once the pain was under control to be followed up in the outpatient clinic after an MRCP.

She was seen in the outpatient clinic with the MRCP results in 2 months' time, which again didn't visualise the gallbladder. This confirmed the diagnosis of GA. CBD measured less than 3 mm in diameter with no filling defects. There was no biliary tree or the main pancreatic duct dilatation noted. In summary MRCP showed a normal bile duct system without the gallbladder (Video 1, Video 2, Video 3, Fig. 1, Fig. 2, Fig. 3). At this point she was having recurrent pains again in the right upper quadrant. The decision was made to further investigate her with a hepatobiliary iminodiacetic acid (HIDA) scan post-partum to look for sphincter of Oddi dysfunction. She had the HIDA scan, 6 months from her initial presentation. This showed normal pattern of tracer uptake by the liver and no gallbladder was seen in the imaging with no features of obstruction to biliary drainage (Fig. 4). She was further followed up with a gastroscopy after the HIDA scan. This was positive for H pylori, otherwise there wasn't any abnormality detected in the scope. She completed the treatment for H pylori. Her pain was minimal at this stage and was settling, hence further investigations were not carried out.

Fig. 1.

MRCP coronal view: with non visualisation of gallbladder.

Fig. 2.

MRCP coronal view: with non visualisation of gallbladder.

Fig. 3.

MRCP reconstructed 3D view of the biliary tree. Cystic duct and gallbladder is not visualised.

Fig. 4.

HIDA scan dynamic 4-minute frame: Radioactive tracer doesn't outline a gallbladder or a cystic duct

3. Discussion

GA is a rare occurrence with an incidence of 0.01–0.02 % in an autopsy series [12]. Wilson et al. suggests that there is a strong hereditary component [13]. GA can be an isolated congenital abnormality or can be associated with other congenital abnormalities in biliary, gastrointestinal, genitourinary systems etc. [14]. According to Stevenson et al., majority are thought to be isolated with an Incidence of 70 % and biliary atresia can be in association in 9 % of the cases [15].

Clinical symptomatology of presentation can be varied. Richards et al. in 1993 describes a review of 44 adult patients with gallbladder agenesis. Commonest presentation was with symptoms of biliary colic (54 %) and dyspepsia (34 %). 27 % presented with jaundice, however ¾ of these patients found to have common bile duct stones [4]. There is paucity of information regarding GA diagnosed during pregnancy.

Diagnosing GA can be challenging. In 1988, Bennion et al. described that patients with non-visualised gallbladder in cholescintigraphy with symptoms of right upper quadrant pain and fever are diagnostic for acute cholecystitis [16]. In early decades, all most all the patients were diagnosed at the time of surgery [17]. However due to the use of preoperative advanced imaging modalities, nowadays the diagnosis is made more often and as a resultant unnecessary surgery can be prevented.

According to literature, even with the availability of sophisticated imaging options, still in some cases, the diagnosis is made during the surgery. This could be due to multiple reasons. These patients present with hepatobiliary symptoms mimicking gallbladder pathology [4]. Most of these patients initially get investigated by an USS to assess the gallbladder. There are three categories of USS findings described in the literature. First is non visualisation of the gallbladder [6]^, [18], second is visualisation of a shrunken or a contracted gallbladder [5]^, [19] and the last is visualisation of a normal gallbladder or a gallbladder with gallstones [15]. Patients whose USS get reported as shrunken or contracted gallbladder or the gallbladder with gallstones have an increased risk of undergoing a surgery.

Surgery can exert high risk in this patient population. As the gallbladder is not found in the normal anatomical position, the chance to explore to look for an ectopic gallbladder is high. Bennion et al. discussed in his review, that once the abdominal cavity is entered and the gallbladder appears absent, the surgeon is responsible to prove gallbladder agenesis by thorough surgical exploration looking for common sites of ectopic gallbladder [16]. As per Sherson et al., these sites run from hepatic hilum to duodenum including intrahepatic, between leaves of the lesser omentum, falciform ligament, retro hepatic, retroperitoneal, retro duodenal and retro pancreatic space [20]. Previous literature has shown complications following operative management in patients with GA.

When USS results shows non-visualisation of the gallbladder or contracted/shrunken gallbladder, it is recommended to investigate further to identify the gallbladder or to diagnose GA [19]. The imaging modality options include MRCP, computer tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound scan (EUS) [19]. Investigating with HIDA scans remains a question, as it could cause false positives due to lack of visualisation of gallbladder.

In this case report, we present a young female presenting with symptoms of biliary colic during her second pregnancy. The USS couldn't visualise the gallbladder, which was initially thought to be due to inadequate fasting status. Hence we repeated the scan the next day with adequate fasting. Once the repeated USS failed to visualise the gallbladder, we considered GA as a differential diagnosis. However, by this time patient symptoms improved with proton pump inhibitors and regular paracetamol. Further investigations with MRCP was arranged to confirm her diagnosis of GA. MRCP demonstrated the absence of gallbladder with normal biliary duct system. Due to radiation risk, especially considering her pregnancy status, we avoided imaging with a CT scan. It is not known whether diagnosis of GA in pregnancy could possibly impose more challenge than a non-pregnant adult due to changing body habitus and gravid uterus. However, pregnancy status could impose challenges in the selection of imaging modalities.

4. Conclusion

In conclusion, GA is rare. Misdiagnosis is possible and can lead to unnecessary surgeries. Appropriate and timely investigations can diagnose GA. One should have high index of suspicion when an USS result shows a non-visualisation of the gallbladder, contracted or a shrunken gallbladder. It is prudent to further investigate this cohort of patients to rule out gallbladder agenesis.

The following are the supplementary data related to this article.

Video 1

MRCP axial cuts with non visualisation of gallbladder.

Video 2

MRCP. Reconstructed 3D view of biliary tree. Cystic duct and gallbladder is not visualised.

Video 3

MRCP axial cuts with non visualisation of gallbladder.

Consent

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.

Ethical approval

Case report was written in retrospect. Patients' anonymity is maintained throughout. Ethical approval not required in our institution to publish anonymous case reports.

Funding

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

Guarantor

MYP Pinto.

Research registration number

Not applicable.

CRediT authorship contribution statement

• MYP Pinto: Conceptualization, Writing – Original draft, Writing – Review & editing, Validation

• S Neelankavil: Writing - Review & editing, Supervision, Validation.

Declaration of competing interest

The authors have no competing interests to disclose.