A huge primary peritoneal papillary adenocarcinoma which demonstrated imaging findings similar to those of extrahepatic-growing type hepatic tumor: report of a case.

We herein report a 69-year-old woman who presented with a huge intra-abdominal tumor which demonstrated imaging findings similar to those of extrahepatic-growing type hepatic tumor, but turned out to be primary peritoneal papillary adenocarcinoma. Computed tomography showed a well-demarcated mass, measuring 12.0 cm in diameter, which came in contact with the lateral segment of the liver and invaded the diaphragm and abdominal wall. Distant lymph node metastasis was also detected. A fine-needle aspiration biopsy of the tumor showed poorly differentiated adenocarcinoma of unknown origin. After chemotherapy with 5-fluorouracil and cisplatin, the maximal diameter of the tumor decreased to 6.0 cm. The patient then underwent a tumorectomy together with a lateral segmentectomy of the liver, a splenectomy, a partial resection of the diaphragm and abdominal wall, and a left oophorectomy. Histological and immunohistochemical examinations demonstrated the tumor to be primary peritoneal papillary adenocarcinoma.