The clinicopathologic and immunohistochemical characteristics of ampulla of Vater carcinoma: the intestinal type is associated with a better prognosis.

BACKGROUND/AIMS: We wanted to compare the clinicopathological parameters with the immunohistochemical expression patterns and patient survival for the intestinal type (IT) and the pancreatobiliary type (PT) of ampulla of Vater carcinoma. Ampulla of Vater carcinoma can be classified histologically into either IT or PT. The biologic behavior and patient prognosis vary considerably in relation to the tumor type.

METHODOLOGY

From September, 1995, to February, 2004, 34 patients with the pathologic diagnosis of ampulla of Vater carcinoma were retrospectively reviewed and the prognostic factors were analyzed. To classify the phenotypes of the tumors, the keratin types (CK7 and CK20), the type of apomucin of the mucosa (MUC2), and the glucose transporter (GLUT1) were studied for differentiating the tumor types.

RESULTS

The 5-year survival rate of the 34 patients with ampulla of Vater carcinoma was 58.8%. Histologically, 12 patients had IT and 22 had PT, and the IT patients all survived. The long-term survival after resection of the tumor was significantly greater for the patients with IT than for the patients with PT. Although these differences were not statistically significant, the prognosis of IT group seemed more favorable (p = 0.0955). On the immunohistochemical staining, MUC2 (p < 0.0001), CK20 (p = 0.0002) and CK7 (p = 0.0368) were statistically effective, but not GLUT1, for differentiating IT from PT.

CONCLUSIONS

For the classification of the tumor phenotypes, performing immunohistochemical staining were helpful to differentiate the two types of tumor. A study with a larger number samples would probably elucidate the different clinical course between these two types of ampulla of Vater carcinoma.