Incidental gallbladder mucocele mimicking acute cholecystitis: A case report and review of literature

Abstract

BACKGROUND

Gallbladder mucocele, also known as gallbladder hydrops, is a rare condition characterized by the distention of the gallbladder due to the accumulation of fluid or mucus within its lumen, primarily attributed to obstruction arising from a gallstone in the cystic duct or gallbladder neck.

CASE SUMMARY

We present a case of a 67-year-old woman with an incidentally discovered gallbladder mucocele, shedding light on the clinical presentation, causes, and histopathological findings. We performed a literature review including an analysis of 27 case reports, revealing the diverse spectrum of causative factors, clinical manifestations, diagnosis, and management.

CONCLUSION

This study underscores the importance of considering alternative diagnoses and highlights the significance of imaging techniques in narrowing down the differential diagnosis and histopathologic examination for a definitive diagnosis.

Key Words: Gallbladder diseases; Gallstones; Mucocele; Cholecystitis; Case report

Core Tip: Gallbladder mucocele (GBM) is a rare condition characterized by gallbladder distension due to mucus accumulation, often mimicking acute cholecystitis. This case report presents a 67-year-old woman diagnosed incidentally with GBM following cholecystectomy. A comprehensive literature review of 27 cases highlights diverse etiologies, clinical presentations, and optimal management strategies. Early diagnosis and elective surgical intervention are crucial for preventing complications. This study contributes to surgical literature by consolidating findings on GBM and proposing evidence-based management pathways.

INTRODUCTION

Gallbladder mucocele (GBM), also known as gallbladder hydrops, refers to distention of the gallbladder due to the accumulation of mucus or fluid within the lumen[1-3]. This condition is typically caused by an obstructive process, most commonly due to a gallstone lodged in the gallbladder neck or cystic duct[1,4], which impedes normal bile flow and leads to mucus accumulation. However, obstruction can also result from other etiologies such as inflammation or neoplasia, which contribute to increased intraluminal pressure and subsequent mucosal injury. A clear understanding of bile flow dynamics and mucus secretion mechanisms is essential to elucidate the pathophysiology of GBM and guide effective treatment strategies. GBM is most frequently identified incidentally during surgical procedures[5]. It is a rare condition in humans, though associations have been reported with Epstein-Barr virus infection and Kawasaki disease[1]. Interestingly, GBM is much more commonly observed and extensively studied in veterinary medicine, particularly in dogs, where numerous cases have been documented[3,6-9].

We report the case of a 67-year-old woman who presented with nausea associated with intermittent coughing. Imaging revealed a hydropic gallbladder without wall thickening, pericholecystic inflammation, or cholelithiasis. The common bile duct was dilated, and endoscopic ultrasound demonstrated an irregular stone obstructing the proximal cystic duct. The patient underwent laparoscopic cholecystectomy, and histopathological examination confirmed the diagnosis of GBM. This case highlights the rarity of GBM in humans and underscores the importance of recognizing its imaging features. We also provide a comprehensive review of the existing literature, including analysis of case reports from 27 studies. This surgical case report has been prepared and reported in accordance with the surgical case report guidelines.

CASE PRESENTATION

Chief complaints and history of past illness

A 67-year-old woman, with a history of anxiety, osteoporosis, hyperlipidemia, and Grave’s hypothyroidism (status post thyroidectomy) presented to Holtz center with nausea associated with cough, a few times per month.

History of present illness

She also had diarrhea episodes, noting that dairy products worsened her symptoms, and mild postprandial discomfort. She denied fever, chills, vomiting, abdominal pain, acid reflux symptoms, early satiety, rectal bleeding, or any genitourinary symptoms. She also mentioned that she had lost approximately 10 pounds (4.5 kg) in the past month.

Surgical history

She had a history of cesarean section, hernia sac repair, and thyroidectomy. She had no known allergies. She never smoked or used illicit drugs. She drinks socially.

Family history

No significant family history was noted.

Physical examination

Vital signs on presentation were within normal ranges. The patient’s body mass index was 19.02 kg/m². The physical examination was unremarkable.

Laboratory examinations

Laboratory tests (including complete blood count with differential, amylase, lipase, complete metabolic panel, prothrombin time, partial thromboplastin time, and urinalysis) were all within normal limits.

Imaging examinations

Computed tomography (CT) scan of the abdomen and pelvis revealed dilatation of the central biliary ducts tapering smoothly towards the ampulla without a discrete obstructing lesion. The gallbladder was distended without wall thickening or acute inflammation (Figure 1). Magnetic resonance imaging without contrast was also performed showing a hydropic gallbladder without wall thickening or pericholecystic inflammatory changes. The common bile duct was dilated measuring up to 10 mm in the proximal third of the duct with smooth gradual tapering to normal caliber towards the ampullary region. No choledocholithiasis was identified (Figure 1). The differential included a cystic duct stone, polyp, or cholangiocarcinoma. Upper endoscopic ultrasound showed dilation in the upper third of the main bile duct which measured up to 10 mm. The duct had a smooth distal taper to the ampulla. No choledocholithiasis was noted. One irregular hyperechoic stone was visualized endosonographically in the proximal cystic duct measuring 11 mm in greatest dimension (Figure 2).

Figure 1 Computed tomography scan and magnetic resonance imaging without contrast image studies. A: Computed tomography scan of the abdomen and pelvis demonstrating dilatation of the central biliary ducts tapering smoothly towards the ampulla without a discrete obstructing lesion. The gallbladder is distended without wall thickening or acute inflammation; B: Magnetic resonance imaging without contrast shows a hydropic gallbladder without wall thickening or pericholecystic inflammatory changes. The common bile duct is dilated measuring up to 10 mm in the proximal third of the duct with smooth gradual tapering to normal caliber towards the ampullary region. No choledocholithiasis has been identified.

Figure 2 Upper endoscopic ultrasound showing dilation in the upper third of the main bile duct which measured up to 10 mm. A: The duct had a smooth distal taper to the ampulla. No choledocholithiasis was noted; B: One irregular hyperechoic stone was visualized endosonographically in the proximal cystic duct measuring 11 mm in greatest dimension.

FINAL DIAGNOSIS

The gross pathologic examination showed a gallbladder that measured 12.1 cm × 3.7 cm × 2.9 cm (Figure 3). The serosal surface was tan, pink with focal areas of hemorrhage, with prominent vessels. A round yellow calculus that measured 1.2 cm × 1.2 cm × 1.1 cm was found to be impacted and blocking the cystic duct. The gallbladder wall measured 0.1 cm in maximum thickness. Histopathological examination showed a gallbladder almost entirely forming a cyst with atrophic cuboidal epithelium (Figure 4). A diagnosis of mucocele of the gallbladder was made.

Figure 3  Gross image of the gallbladder.

Figure 4 Microscopic images of the gallbladder mucocele. A: Hematoxylin and eosin-stained sections of the gallbladder mucocele wall; B: High-power hematoxylin and eosin-stained section of the mucocele wall lining showing atrophic cuboidal epithelium.

TREATMENT

A laparoscopic cholecystectomy was performed with a negative intra-operative cholangiogram.

OUTCOME AND FOLLOW-UP

The patient had an uneventful postoperative course, with no complications observed. She recovered well, and regular follow-up assessments confirmed a smooth recovery, with no signs of recurrence or ongoing symptoms.

DISCUSSION

GBM, also known as gallbladder hydrops, refers to distention of the gallbladder resulting from the accumulation of mucus or clear fluid within the lumen[1,2]. The clinical presentation of GBM is typically nonspecific and often mimics acute cholecystitis[2]. We conducted a comprehensive literature review of published case reports on GBM, focusing on human studies from 1946 to the present. The review included systematic searches of PubMed, Web of Science, and Google Scholar using the term “gallbladder mucocele”. Inclusion criteria were case reports of GBM in human subjects with adequate clinical data; studies without focus on GBM or lacking sufficient clinical detail were excluded.

A total of 27 relevant studies were identified, including our current case. Among these, 16 patients were male and 12 were female, with a majority of cases occurring in the pediatric population. Of the 27 cases, 17 patients presented with abdominal pain, most commonly in the right upper quadrant, but also in the epigastric or periumbilical areas (Table 1). Nausea and vomiting were frequently reported. Notably, some patients had concurrent Kawasaki disease, typically presenting with fever and lymphadenopathy, likely attributable to Kawasaki disease rather than GBM. In four cases, patients presented with a right upper quadrant mass[10-13], while one had a pelvic mass[4]. Anorexia was reported in three patients[14-16].

Table 1 Summary of the 27 cases reported in literature.

Ref.	Demographics and clinical presentation	Kawasaki disease	Gallstones	Histopathology	Complications	Imaging	Management
Pack and Teng[12], 1968	61-year-old male with cystic duct carcinoma	No	No	Mucosal flattening, ulceration, and inflammation		Cholecystography	Cholecystectomy and cystic mass removal
Magilavy et al[24], 1978	6-year-old female with fever and sore throat	Yes	No			Ultrasound	Methicillin
Magilavy et al[24], 1978	8-year-old male with swollen cervical lymph node and fever	Yes	No	Fibrinous exudate and inflammation		Ultrasound, laparotomy	Cholecystectomy
Kumari et al[29], 1979	5-year-old male with fever, swollen cervical lymph nodes, rash, and vomiting	Yes	No			Ultrasound	Cholecystectomy
Liebmann et al[17], 1982	25-year-old male with malaise, left anterior cervical neck pain and swelling, sore throat, and nonproductive cough	Yes	No			Ultrasound	Erythromycin
McCrindle et al[30], 1988	3.5-year-old male with Henoch-Schoenlein syndrome; presenting with cough, RUQ pain, rhinorrhea, vomiting, and generalized aches	No	No			Ultrasound	Prednisone
Bishop and Kao[21], 1991	6-year-old male with periumbilical pain, fever, and vomiting	Yes	No			Ultrasound, HIDA scan	IVIG
Crankson et al[31], 1992	6-year-old male with liver cirrhosis secondary to giant cell hepatitis; presenting with RUQ pain, vomiting, and diarrhea	No	No			Ultrasound	Cholecystostomy; patient expired due to cardiopulmonary arrest
Westrope and Acharya[20], 2001	3-year-old female with cryptosporidium infection; presenting with vomiting and malodorous watery diarrhea	No	No	Hepatobiliary involvement by cryptosporidium infection		Ultrasound	Fluids and antibiotics
Herek and Yildiran[23], 2001	8-year-old male with abdominal pain status post nonpenetrating trauma to RUQ	No	No	Gallbladder mucosa with ulcerations		Ultrasound	Blood transfusion and cholecystectomy
Khothsymuong and Kaminski[4], 2004	Elderly man (age not reported) with malaise, chest pain, and weight loss	No	Yes			Ultrasound	Patient expired
Egritas et al[16], 2007	3-month-old female with fever and inappetence	Yes	No			Ultrasound	IVIG
Gucev et al[13], 2011	24-year-old male with Wilson’s disease; presenting with RUQ pain and mass, swelling of the right talocrural articulation	No	No			Ultrasound	Cholecystectomy; penicillamine; alpha tocopherol, and vitamins B, K and C
Zong et al[11], 2013	55-year-old female with RUQ mass, abdominal distention, and epigastric discomfort	No	No	Gallbladder wall lined by columnar epithelium; inflammation		Ultrasound	Laparotomy and drainage
Aldaghi et al[22], 2015	5-year-old male with jaundice, fever, vomiting, and RUQ pain	No	No		Viral hepatitis	Ultrasound	Antibiotics: Ceftizoxime and metronidazole
Albu et al[32], 2016	52-year-old male RUQ pain, fever, fatigue, and weakness	No	Yes		Simultaneous toxic hepatitis	Ultrasound	Laparoscopic cholecystectomy
Clemente et al[19], 2017	53-year-old female with right hypochondrium pain	No	No	Heterotopic intestinal mucosa		Ultrasound and CT	Laparoscopic cholecystectomy
Yadav and Kankaria[33], 2017	46-year-old female with RUQ pain	No	Yes	Chronic cholecystitis		Ultrasound	Laparoscopic cholecystectomy
Reyes et al[34], 2017	39-year-old female RUQ pain with postprandial epigastric pain	No	Yes	Suppurative gallbladder mucocele, acute on chronic cholecystitis		Ultrasound and MRCP	Laparoscopic cholecystectomy
Chaly et al[18], 2017	48-year-old male with liver transplantation; presenting with RUQ pain	No	No	Inflammation, fibrosis, and granulation tissue formation		MRCP, ERCP, and CT	Laparoscopic cholecystectomy
Sun et al[25], 2018	6-year-old male with Kawasaki disease; presenting with fever, rash, stiff neck, diffuse abdominal pain, fatigue, and acholic stool	Yes	No			Ultrasound	IVIG and aspirin for treatment of Kawasaki disease
Kılıç et al[35], 2018	7-year-old male with RUQ pain, fever, vomiting, and diarrhea	Yes	No			Ultrasound	IVIG and aspirin for treatment of Kawasaki disease
Loh et al[14], 2019	63-year-old male with inappetence, weight loss, and intermittent vomiting	No	Yes		Gastric outlet obstruction	CT and MRCP	Open cholecystectomy
Valecha[15], 2019	27-year-old female abdominal pain, vomiting, and lack of appetite	No	Yes	Fibrosis of the wall		Ultrasound	Laparoscopic cholecystectomy
Sharma et al[36], 2021	50-year-old female with RUQ pain	No	Yes			CT and ultrasound	Morphine and ondansetron
Ganta et al[37], 2022	67-year-old female RUQ and mid abdominal pain, nausea, vomiting	No	Yes			Ultrasound, MRCP	Laparoscopic cholecystectomy
Le et al[10], 2023	56-year-old female lower abdominal pressure, nausea, indigestion, and urinary urgency	No	Yes	Fibrosis, inflammation, thickened muscularis propria, Rokitansky-Aschoff sinuses, and attenuated mucosa		Ultrasound and CT	Laparoscopic cholecystectomy and intraoperative cholangiogram

RUQ: Right upper quadrant; HIDA: Hepatobiliary iminodiacetic acid; IVIG: Intravenous immunoglobulin; CT: Computed tomography; MRCP: Magnetic resonance cholangiopancreatography.

Under normal physiological conditions, the gallbladder stores bile produced by the liver and releases it after meals, particularly after consumption of fatty or spicy foods. Bile flows through the cystic duct into the duodenum. Dysfunctional bile release may lead to stone formation and eventual obstruction of the cystic duct. If this obstruction is complete, the gallbladder mucosa reabsorbs bile salts, resulting in accumulation of clear, colorless mucus within the lumen[1,2]. This mechanism was proposed as the underlying pathophysiology in 10 of the reviewed cases.

In seven cases, patients were diagnosed with Kawasaki disease, where cystic duct obstruction was presumed secondary to external compression by enlarged lymph nodes[17]. Other reported etiologies of cystic duct obstruction leading to GBM included: Liver transplantation[18], gallbladder polyps[19], cryptosporidial hepatobiliary infection[20], impaired gallbladder contractility following meals[21], immune-mediated cholecystitis post-hepatitis A infection[22], congenital giant gallbladder[11], blunt trauma[23], cystic duct carcinoma[12], and Wilson’s disease[13]. In some cases, the gallbladder wall showed inflammation and bacterial colonization in up to 30% of cases[2], and Rokitansky-Aschoff sinuses were present in up to 90%[2]. Histopathologic findings also included cystic mucinous hyperplasia[5]. Acute and chronic cholecystitis were reported in five cases[10-12,15,24]. One case was associated with cystic duct carcinoma[12], and another with traumatic hemobilia[23]. However, in several reports, the gallbladder showed no signs of inflammation[25]. GBM is generally a benign and incidental finding[1], but its clinical presentation can mimic acute cholecystitis. Therefore, it is essential to rule out other etiologies. Laboratory results are usually normal in chronic cholecystitis with mucocele[2], though in acute presentations, leukocytosis and elevated liver enzymes may be observed[2].

Imaging plays a crucial role in diagnosis. CT and magnetic resonance imaging provide detailed views of the biliary system, highlighting gallbladder distention, wall thickening, or inspissated bile. These modalities can also detect associated pathologies such as biliary obstruction or hepatic involvement, which are important in guiding management. Common radiologic findings include gallstones, gallbladder enlargement, pericholecystic fluid, and cystic duct obstruction[1]. Hepatobiliary iminodiacetic acid scanning can be useful to assess gallbladder function, often showing a 0% ejection fraction in cases of obstructed GBM[2]. Among the 27 analyzed cases, ultrasound was used in 24, CT in 5, magnetic resonance cholangiopancreatography in 3, and hepatobiliary iminodiacetic acid scan in 1. One older case from 1968 utilized cholecystography[12].

Treatment of GBM centers on addressing the underlying cause, most commonly gallstones. Initial management may include dietary modifications (e.g., reduced fat intake), but definitive treatment is laparoscopic cholecystectomy. This approach is favored for its minimally invasive nature, associated with reduced postoperative pain, shorter hospital stays, and faster recovery. In high-risk surgical patients, percutaneous cholecystostomy may serve as a temporary measure. Fluid aspiration before cholecystectomy has been associated with reduced morbidity. Among the reviewed cases, elective cholecystectomy was performed in 12. For those with Kawasaki disease, intravenous immunoglobulin therapy was administered (Table 1)[2,26].

Postoperative care is essential for long-term outcomes. While cholecystectomy typically resolves symptoms, patients may develop post-cholecystectomy syndrome, characterized by dyspepsia and gastrointestinal discomfort. There is also an increased risk for metabolic syndrome and cardiovascular disease. Long-term follow-up and lifestyle interventions, including dietary changes, are important to minimize these risks and promote optimal recovery[27,28].

CONCLUSION

This case report and comprehensive literature review shed light on the rare but clinically significant condition of GBM. Early recognition and appropriate management are essential for favorable outcomes. While the majority of cases are benign, the broad differential and potential complications underscore the need for accurate diagnosis and timely surgical intervention. Further research is needed to clarify the underlying mechanisms, refine diagnostic tools, and develop evidence-based management strategies for GBM.