Different distribution of CA19-9 in carcinomas arising in the papilla of Vater. An immunohistochemical study.

The origin and pathogenesis of the carcinoma of the Vater's papilla were estimated by immunohistochemically analysing the distribution of CA19-9 in the tumor tissue. The material comprised surgical specimens from 29 patients with carcinoma of the Vater's papilla, 15 with carcinoma of the pancreas, 24 with carcinoma of the bile duct and two with carcinoma of the duodenum. A non-invasive adenomatous component (NAC) was shown to coexist with carcinoma of the Vater's papilla in 14 patients. Besides, normal papilla of Vater from ten autopsy cases were added as control. The presence of CA19-9 in the tissue was demonstrated by ABC method using a monoclonal antibody. The epithelia of normal pancreatic and bile ducts showed diffuse distribution of CA19-9, while at the common channel and the orifice of the papilla it was partially distributed. CA19-9 was not demonstrated in the duodenum. The NAC-positive carcinoma of the papilla of Vater showed partially distributed CA19-9. In contrast, NAC-negative carcinoma of the Vater's papilla and carcinomas of the pancreas and bile duct showed diffuse distribution of CA19-9. Moreover, the level of serum CA19-9 in most of the patients with NAC-positive carcinoma of Vater's papilla remained within the normal limit, while in patients with NAC-negative carcinoma, or with carcinoma of the pancreas or bile duct, the level was higher. Thus it was speculated that NAC-positive carcinoma of Vater's papilla may arise from the common channel, the orifice of the papilla, or the duodenum acquiring antigenicity against CA19-9 during the cancer development. On the other hand, NAC-negative carcinoma of the Vater's papilla may originate from the pancreatic or bile ducts.