Background: Carcinosarcoma of the ampulla of Vater is extremely rare, and to the best of our knowledge, this is the third reported study.
Case presentation: The patient was a 73-year-old man, who presented with a chief complaint of dark urine. After a work-up, we suspected duodenal papillary cancer and performed a subtotal stomach-preserving pancreaticoduodenectomy with lymph node dissection. Immunohistochemically, the sarcomatous atypical cells were diffusely positive for cytokeratin AE1&3 and vimentin and focally positive for α-smooth muscle actin; these cells were also negative for desmin, CD34, DOG1, c-kit, and S100. From these findings, we diagnosed the patient with so-called carcinosarcoma. There was no lymph node metastasis.
Conclusions: Carcinosarcoma of the ampulla of Vater has a poor prognosis, and lymph node metastases are often seen. For the complete cure of carcinosarcoma of the ampulla of Vater, resection with the dissection of the lymph nodes may be necessary.
Keywords: Ampulla of Vater; Carcinosarcoma; Pancreaticoduodenectomy.