Abstract
A 73-year-old woman consulted our department for prolonged liver dysfunction following cholangitis. Although upper abdominal CT and MRI revealed no abnormalities, an irregular low-echo nodule of 10mm was detected in the duodenal papillary area by EUS. Abnormal wall findings were apparent in the papillary area bile duct by ERCP, wherein IDUS disclosed the presence of a nodule. A poorly differentiated adenocarcinoma was diagnosed based on the results of EST and biopsy. As no signs of tumor were noted in the papillary opening, a diagnosis of ampullary carcinoma of non-exposed protruded type was made, necessitating pylorus-preserving pancreaticoduodenectomy. Pathological findings indicated an adenocarcinoma with invasive micropapillary carcinoma (IMPC). The size of the lesion was 9mm, which had marked lymphatic vessel invasion and lymph node metastasis. Based on these observations, careful lymph node dissection is recommended when encountering IMPC in biopsy tissue samples.
