Biliary Granular Cell Tumor

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Granular cell tumor (GCT) is a benign neoplasm showing neuroectodermal differentiation and is most commonly found in the head and neck region, including the tongue. 1 This tumor is now believed to occur in virtually any site of the body, including skin, breast, and gastrointestinal tract, with less than 1% developing in the biliary tract. 2 To our knowledge, only one case of GCT of the biliary tract has been reported in Korea, which occurred in the gallbladder. 3 Herein, we present another case of GCT of the biliary tract. A 62-year-old female was referred to our hospital for management of gastric adenocarcinoma that had been found during a periodic health examination. She had been receiving treatment for hypertension and diabetes mellitus for 20 years. Abdominal computed tomography for a diagnostic workup revealed focal dilatation of the right posterior hepatic duct, and subsequent imaging with magnetic resonance imaging and magnetic resonance cholangiopancreatography showed a stricture at the right hepatic duct (Fig. 1A). Laboratory findings were unremarkable. Under the presumptive diagnosis of synchronous cholangio-carcinoma and gastric carcinoma, she underwent hepatic right lobectomy with radical subtotal gastrectomy. On a resected specimen , a 0.9×0.4 cm sized, ill-defined, nonencapsulated tumor was noted in the extrahepatic portion of the right hepatic duct (Fig. 1B). The bile duct mucosa was grossly intact, and the tumor was located in the submucosal layer. The cut surface of the tumor was gray to whitish, solid, firm, and infiltrative (Fig. 1C). The margins were clear on frozen biopsy. On microscopic examination , the tumor was composed of large polygonal cells with abun dant eosinophilic granular cytoplasm, and the nuclei were small, dark, uniform, and centrally located (Fig. 2A, B). The overlying mucosa was atrophic and showed autolysis (Fig. 2A). The tumor cells were diffusely positive for periodic acid-Schiff (PAS), CD68, and S100 protein (Fig. 2C). A diagnosis of GCT was made. The stomach tumor was papillary adenocarcinoma (pT1N0Mx). The patient remains healthy at 20 months after the resection, without any signs of complication. DISCUSSION The first case of GCT was reported by Abrikossoff in 1926 in the skeletal muscle of the tongue. 4 Since then, there have been some discrepancies regarding the …