A Rare Case of Biliary Synovial Sarcoma

Abstract

A 51-year-old Hispanic male was referred to our hospital with obstructive jaundice and a possible cholangiocarcinoma. At the other hospital patient had undergone laboratory examination, CT scan and ERCP. Laboratory examination showed leucocytosis, elevated liver function tests (total bilirubin 14 mg/dl, conjugated bilirubin 10 mg/dl, and alkaline phosphatase of 800 U/per liter). Computed tomography (CT) abdomen showed dilated CBD and a mass obstructing the neck of gall bladder. During endoscopic retrograde choledochopancreatography (ERCP) lots of mucus membrane like material was expressed and sent to histopathology. No definitive pathological diagnosis could be made because of the complexity of the tissue. Patient continued to be symptomatic and had persistently elevated LFTs. After transfer, MRCP with gadolinium revealed an intraluminal mass within the common bile duct with probable extension into the gallbladder, most consistent with cholangiocarcinoma (Fig. 1). Patient underwent Whipple's procedure for this suspicious mass. Gross pathology of the resected specimen revealed two separate unconnected polypoid masses in common bile duct and gall bladder. Histopathology revealed whorls of small darkly staining cells arranged in sheets suggestive of synovial sarcoma vs. small cell carcinoma vs. peripheral neuroectodermal tumor (PNET) (Fig. 2). Various immunohistochemical stains were performed on the tumor specimen (positive for CD 99, Bcl-2 and synatophysin) favoring a poorly differentiated synovial sarcoma. Slides were reviewed with two other pathologists who concurred with the interpretation of the tumor as synovial sarcoma. To the best of our knowledge this is one of the first rare cases described in literature. Patient was lost to follow-up before initiation of chemotherapy.[figure1][figure2]FigureFigure