Hepatoid carcinoma of the pancreas mimicking neuroendocrine tumor

A 44-year-old man was admitted to our hospital for further investigation of a tumor in the pancreatic head. He had no symptoms or chronic liver diseases. Pancreatic hormones, CEA, and CA19-9 were normal. Serum alpha-fetoprotein and des-gamma-carboxy prothrombin were not assessed.

A contrast-enhanced abdominal CT scan revealed a well-circumscribed, comparatively hypervascular mass during the arterial phase of imaging (panel A), suggesting a neuroendocrine tumor of the pancreas.

The patient underwent tumor enucleation. A macroscopic examination revealed a 19 mm × 18 mm solid tumor with a fibrous capsule and a nodule-in-nodule appearance (panel B). A H&E staining revealed the tumor cells contained abundant eosinophilic cytoplasm and exhibited a trabecular pattern with bile production (arrow heads) (panel C, 50×). Immunohistological examinations revealed the tumor cells were positive for Hep Par 1 and glypican 3 (panel D, 50×) and negative for synaptophysin and chromogranin A. We diagnosed the tumor as a hepatoid carcinoma of the pancreas.

Acknowledgements

The authors thank Dr. Takeshi Uehara, a pathologist at the Department of Laboratory Medicine, Shinshu University Hospital, for his help with the pathological interpretation and final diagnosis.

Footnote

Conflicts of Interest: The authors have no conflicts of interest to declare.

Informed Consent: Written informed consent was obtained from the patient for publication of this manuscript and any accompanying images.