IgG4-Sclerosing Cholangitis Masquerading as Cholangiocarcinoma: A Case Report

02 Apr 20264 min read0 viewsJournal Feed

GIST

BackgroundImmunoglobulin G4-related disease (IgG4-RD) is an immune-mediated chronic fibroinflammatory condition that can affect multiple organ systems. IgG4-related sclerosing cholangitis (IgG4-SC) is its manifestation involving the biliary tract.

Due to atypical clinical presentations in some cases and insufficient awareness among clinicians, IgG4-SC is frequently misdiagnosed as cholangiocarcinoma, and multiple instances of inappropriate treatment as a result have been documented.Case presentationHere we report a case of IgG4-SC that presented diagnostic challenges preoperatively and was followed by rare pancytopenia after surgery. The patient was a 50-year-old man who sought medical attention due to elevated transaminases for eight months, without obvious clinical symptoms.

Among serum tumor markers, the level of protein induced by vitamin K absence/antagonist-II (PIVKA-II) was elevated. Examinations including magnetic resonance cholangiopancreatography (MRCP), contrast-enhanced abdominal computed tomography (CT), and positron emission tomography-computed tomography (PET-CT) all suggested malignant stricture at the hepatic hilum.

A needle biopsy indicated dysplastic changes but was inconclusive for cholangiocarcinoma. Although IgG4-SC was considered, multiple serum IgG4 measurements remained within the normal range.

With an initial clinical diagnosis of cholangiocarcinoma, the patient underwent surgical resection.

Clinical Editorial

Clinical context and diagnostic challenge

IgG4-related disease can involve the biliary tract as IgG4-sclerosing cholangitis (IgG4-SC), with variable presentations that may mimic cholangiocarcinoma.
This case centers on a 50-year-old man with eight months of elevated liver enzymes and no clear symptoms; imaging suggested malignant hilar stricture, and a biopsy showed dysplasia but no definitive cholangiocarcinoma.
Serum IgG4 levels were repeatedly within the normal range, complicating preoperative differentiation between IgG4-SC and malignancy.

Imaging, biopsy, and surgical decision-making

Multimodal imaging (MRCP, contrast-enhanced CT, PET-CT) raised suspicion for cancer in the hepatic hilum.
A percutaneous needle biopsy demonstrated dysplastic changes but did not confirm cholangiocarcinoma.
Preoperative consideration included IgG4-SC; however, normal IgG4 values and imaging led to an initial clinical diagnosis of cholangiocarcinoma, prompting surgical resection.
Intraoperative frozen section favored an inflammatory process rather than malignancy, yet definitive diagnosis awaited postoperative pathology.

Postoperative course and therapeutic implications

Postoperatively, the patient developed pancytopenia that was refractory to standard supportive measures.
Final histopathology established IgG4-SC as the underlying diagnosis.
Corticosteroid therapy produced normalization of blood counts, transaminases, and bilirubin, indicating responsiveness to immunosuppression.

Key insights and limitations highlighted by the report

IgG4-SC can present with isolated biliary strictures, lack of characteristic symptoms, normal IgG4 levels, and imaging findings that mimic cholangiocarcinoma, underscoring diagnostic difficulty.
The case emphasizes the importance of pursuing preoperative biopsy and thorough histopathological assessment when cholangiocarcinoma is suspected.
When differentiation remains uncertain despite comprehensive evaluation, intraoperative frozen section biopsy may aid real-time decision-making and avoid delays in appropriate treatment.
The report notes a potential hematopoietic manifestation of IgG4-SC, presenting as pancytopenia, which may respond to corticosteroids, suggesting broader systemic involvement in some patients.

Operational and open questions

The possibility of IgG4-SC with normal serum IgG4 levels raises clinical questions about reliance on IgG4 as a screening tool in suspected biliary IgG4-RD.
The balance between proceeding to surgical intervention versus pursuing more extensive preoperative tissue characterization remains a nuanced decision in cases with ambiguous preoperative evidence.
Additional data are needed to define how often IgG4-SC can present with pancytopenia and the role of corticosteroids in resolving such hematologic abnormalities.