Gastrointestinal: Xanthogranulomatous cholangitis diagnosed by endoscopic ultrasound-guided fine-needle aspiration.

Abstract

A man in his 70s with obstructive jaundice was referred to our hospital for further examination. Tumor marker levels were elevated (carbohydrate antigen 19–9: 494 U/mL [normal range: 0–37 U/mL], DUPAN-2: 292 U/mL [0–150 U/mL]) as well as serum IgG4 levels (120 mg/dL [4.5–117 mg/dL]). Computed tomography and magnetic resonance cholangiopancreatography revealed diffuse thickening of the gallbladder wall and a 16-mm gallbladder neck stone as well as stenosis of the proximal common bile duct (CBD) (Fig. 1a–c). Endoscopic retrograde cholangiopancreatography confirmed proximal CBD stenosis (Fig. 1d). Biliary decompression with a plastic stent was successful, and repeated pathological examinations with brush cytology and forceps biopsy revealed no malignancy. Endoscopic ultrasound (EUS) revealed diffuse thickening of the proximal CBD with a gallbladder neck stone (Fig. 2a). Mirrizi syndrome appeared unlikely because the stone did not cause CBD compression. EUS-guided fine needle aspiration (FNA) with a 25-gauge needle to evaluate the diffuse thickening of the proximal CBD revealed marked infiltration by foamy histiocytes and plasma cells (Fig. 2b,c). No IgG4 immunoreactivity was detected in the plasma cells (Fig. 2d). These pathological findings led to a diagnosis of xanthogranulomatous cholangitis for the proximal CBD stenosis, whereas the gallbladder wall thickening was diagnosed as xanthogranulomatous cholecystitis (XGC). The patient had an uneventful course with conservative treatment, which resulted in spontaneous improvement in the CBD stenosis. No recurrence of obstructive jaundice occurred after stent removal. XGC is a gallbladder disease that is presumed to occur secondary to an impacted stone in the gallbladder neck. XGC sometimes involves adjacent organs. Involvement of the CBD, defined as xanthogranulomatous cholangitis, may cause obstructive jaundice and mimic malignancy.1 Pathological findings in xanthogranulomatous cholangitis are characterized by abundant foamy histiocytes with inflammatory cells.2 To our knowledge, our patient is the first to be diagnosed with xanthogranulomatous cholangitis using EUS–FNA, with pathological findings of foamy histiocytes. EUS–FNA has recently shown higher diagnostic ability for biliary strictures compared with endoscopic retrograde cholangiopancreatography.3 If CBD stenosis and gallbladder neck stones are found without a strong suspicion of Mirrizi syndrome, EUS–FNA could contribute to the differential diagnosis of xanthogranulomatous cholangitis from malignancy.