Abstract
An unusual dilatation of the portal vein in a 57-year-old man on a screening examination. Enhanced CT showed an iso-enhanced tumor measuring 5 cm in diameter in the tail of the pancreas, accompanied by portal vein tumor thrombus (PVTT). We suspected tumor other than invasive ductal carcinoma and strongly considered non-functioning endocrine carcinoma with PVTT. The patient underwent distal pancreatectomy and extraction of the PVTT. Pathologically, tumor cells demonstrated ellipsoidal eccentric nuclei and eosinophilic cytoplasm in a rosette-like arrangement and a trabecular pattern. There were 0-1 mitoses/10 HPF. Metastasis to lymph nodes around the splenic artery and a marked vascular invasion were observed. On immunohistochemical analysis, Chromogranin, Synaptophysin and CD56 showed positive staining, while staining for pancreatic hormones was negative. The Ki-67 labelling index was less than 2%. These findings yielded a definitive diagnosis of well-differentiated non-functioning endocrine carcinoma according to the WHO classification. Surgery has resulted in survival without recurrence for 24 months to date. Non-functioning endocrine carcinoma with PVTT is very rare and only 4 cases had been reported previously. Three cases of well-differentiated carcinoma among those 4 cases showed good outcome due to curative resection. Surgical resection should be considered as the primary option for non-functioning endocrine carcinoma with PVTT.
