Hepatocellular carcinoma arising from ectopic liver tissue in the pancreas

Abstract

Liver tissue ectopia is a well-documented phenomenon. Rarely, hepatocellular carcinoma arises from the ectopic liver tissue. In this paper, we report a case of a primary, well-differentiated hepatocellular carcinoma arising from ectopic liver tissue in the pancreas. The patient is a 58-year-old Hispanic man with no history of underlying liver diseases or chronic pancreatic diseases. Patient presented with a several days history of abdominal pain with radiation to his right upper quadrant. Imaging study revealed a 3.7 x 3.3-cm mass in the distal pancreas. No other lesions were identified. Preoperative fine needle aspiration revealed blood and atypical hepatocytes. The patient underwent distal pancreatectomy and splenectomy for suspected neuroendocrine tumor. Gross examination revealed a well-circumscribed 3.3-cm, beige-tan, pseudolobulated tumor with focal areas of hyperpigmentation. A microscopic examination revealed hepatoid cells arranged in a trabecular pattern with focal bile pigment. Immunohistochemistry study showed that the tumor cells were reactive with hepatocyte antigen (Hep par 1), alpha-1 antitrypsin, but negative for synaptophysin and chromogranin. Immunostain for polyclonal carcinoembryonic antigen showed a typical bile canalicular pattern. These results support that this tumor in the pancreas is hepatocellular carcinoma, most likely arising from ectopic liver tissue within the pancreas.

Hepatoid microcarcinoma of the pancreas: A case report and review of the literature

“…The crucial distinguishable feature is whether the tumor has residual normal liver tissue. (9,10) However, there was no normal liver tissue in both cases classified as pancreatic ectopic hepatocellular carcinoma in the literature. Therefore, the distinction between hepatoid carcinoma and ectopic hepatocellular carcinoma remains somewhat arbitrary.…”

“…(9,10,16) The latter occurs rarely and as a late event, so the original hepatic tumor is usually obvious at presentation. (16) Thorough clinical evaluation and imaging excluded this possibility in the current case.…”

“…Although there was no solid evidence, the lack of normal liver tissue around the microcarcinoma favors the possibility of a malignant change of metaplastic cells from uncommitted stem cells rather than from handicapped ectopic liver tissue. (2,9,10) Because of the obscurity of the difference between pancreatic pure hepatoid carcinoma and ectopic hepatocellular carcinoma, pancreatic carcinomas with pure hepatoid features might be regarded as the same group.…”

“…In the pancreas, hepatoid carcinomas are regarded as a heterogeneous group of tumors with or without another histological component, and carcinomas with pure hepatocytic features have been designated variously as hepatoid carcinoma or ectopic hepatocellular carcinoma. (2)(3)(4)(5)(6)(7)(8)(9)(10) To date, only eight such pancreatic carcinomas have been reported. Herein, we describe the ninth case which was small.…”

Omphalocele with ectopic liver forming a mesodermal cyst

“…The ectopic liver probably develops due to the regression and atrophy of the original connections between hepatocyte trabecules and native liver (ectopia in the gallbladder, ligamentum hepatogastricum) (14,15,16) or due to trapping the hepatocytes by adjacent mesenchyma while forming the liver sinusoids (from the cells of pars hepatica) and their subsequent migration to more distant areas (retroperitoneum, umbilicus, etc.) (17). In the case of dorsal budding of the liver tissue before closure of the pleuroperitoneal canal, ectopic liver may occur in the thoracic cavity (oesophagus, pericardium, pleura) (18,19).…”