Carcinosarcoma of common bile duct: A case report

Abstract

Background: Carcinosarcomas of the common bile duct (CBD) are an extremely rare finding in the clinical setting. Based on a review of 12 literatures, 3 cases had the imaging features of ossification. Carcinosarcomas are prone to distant metastasis, as they possess clinical features of both carcinoma and sarcoma, and generally have with a poor prognosis. Due to the small number of cases reported, clinical experience in the diagnosis and treatment of the disease is lacking.

Case summary: The patient was a 75-year-old woman who had experienced recurrent chills with nausea and vomiting for 3 mo. Computed tomography, magnetic resonance imaging, endoscopic ultrasonography and endoscopic retrograde cholangiopancreatography led to the diagnosis of malignant tumor of the CBD. The patient ultimately underwent cholecystectomy, CBD resection, and choledochojejunostomy. Postoperative pathological examination revealed carcinosarcoma of the CBD, and the latest follow-up showed that the patient is recovering well. Based on previous case reports, some carcinosarcoma has ossification characteristics in imaging. If it is misdiagnosed as biliary calculi, the use of laser lithotripsy in surgery may lead to tumor diffusion. Choledochoscopy and narrow band staining of mucosa are very important for diagnosis.

Conclusion: We herein present a rare case of carcinosarcomas of the CBD, we found the tumours may have imaging features of polypoid growth and ossification only when the sarcomal components are bone differentiation, while show soft tissue shadow when non bone differentiation. Confirmation of diagnosis depends greatly upon postoperative pathological examination and the adjuvant treatment has not been established, which leads to the poor prognosis.

Keywords: Carcinosarcoma; Case report; Common bile duct tumor; Extrahepatic bile duct tumor; Sarcocarcinoma; Sarcomatoid carcinoma.

Figure 1

Imaging revealed an occupying lesion of the middle segment of the common bile duct. A: Computed tomography showed localized thickening with iso-low signal nodules in the middle part of the common bile duct (CBD), approximately 12 mm × 13 mm in size. The nodules were significantly enhanced heterogeneously; B and C: Magnetic resonance imaging by the (B) coronal plane FIESTA sequence and (C) magnetic resonance cholangiopancreatography revealed dilation of the intrahepatic duct and CBD, a soft tissue mass signal at the lower end of the CBD (with rough edge), limited diffusion on weighted imaging, and low signal intensity on apparent diffusion coefficient mapping.

Figure 2

Endoscopic ultrasound showed solid occupancy of the middle segment of the common bile duct, partial compression of the portal vein, The intrahepatic bile duct was widened, to approximately 6 mm in diameter. A: Solid mass of common bile duct, upper common bile duct dilatation; B: An enlarged lymph node next to the common bile duct, approximately 12.9 mm in size; C: Occupancy elastic imaging shows medium texture.

Figure 3

Endoscopic retrograde cholangiopancreatography was recommended for bile duct biopsy and a 7.5 Fr × 7 cm bile duct plastic stent was implanted.

Figure 4

Intraoperative exploration revealed a tumor located in the middle and lower part of the common bile duct. A: Cauliflower-like new organisms approximately 2 cm × 1.5 cm with a hard texture; B: Cholecystectomy, common bile duct resection, and choledochojejunostomy were performed.

Figure 5

Postoperative pathological examination revealed carcinosarcoma of the common bile duct with a tumor volume of 1.0 cm × 0.6 cm × 0.6 cm. Cancerous tissue accounted for 40% and sarcoma for 60% of the tissue. A: Heterotypic glands can be seen in the mucosa of the bile duct, and infiltrating growth can be seen. Adenocarcinoma can be seen in the muscle wall of the bile duct; B: The muscle wall stroma of bile duct can be composed of heterotypic large cells, epithelial cancer nests and sarcoma-like components; C: Sarcoma-like area, large nuclear heterotypic cells in various forms and pathological mitotic image can be seen.

Figure 6

Immunohistochemical examination findings. A: The tissue was positive for carbohydrate antigen 19-9; B: The tissue was positive for CK7; C: Ki-67 was approximately 40%; D: The tissue was positive for Calponin; E: The tissue was positive for CK19; F: The tissue was positive for CKpan; G: The tissue was positive for vimentin; H: The tissue was positive for S-100p; I: The tissue was negative for spinal muscular atrophy.