Carcinoid tumors of the duodenum and ampulla of vater: a clinicomorphologic, immunohistochemical, and cell kinetic comparison.

Carcinoid tumors of the ampulla of Vater (ACs) differ from duodenal carcinoid tumors (DCs). A search for AC and DC was made between 1980 and 2000. The clinicopathologic features and follow-up were assessed. Immunohistochemistry for panneuroendocrine markers, hormone products, proliferating cell nuclear antigen (PCNA), Ki- 67, p21(cip1), and p27(kip1) were performed. A blind proliferative index counting 500 cells was made. Differences were contrasted using the Fisher exact and 2-sided Student t test. Five ACs and 8 DCs were identified in 9 women and 4 men with median ages of 59 and 64 years and mean tumor diameters of 1.6 and 1.85 cm, respectively. All patients with AC presented jaundice, and most patients with DC were asymptomatic (P = .047). Metastases were present in 4 ACs and 1 DC (P =.03). Tumor cells expressed synaptophysin and chromogranin in 60% of ACs and in 100% and 87% of DCs. Gastrin was expressed in 75% of DCs and 20% of ACs (P < .05). The mean value for PCNA index was 4.0% in ACs and 3.2% in DCs, and mean values for Ki-67 were 12.2% and 10.2%, respectively (P = NS). Expression of p21(cip1) and p27(kip1) was observed in 40% of ACs and 37.5% and 12.5% of DCs. Three of 5 patients with AC died of the disease within an average of 11 months, and none of the patients with DC had died at 103 months of follow-up. The more aggressive behavior of ACs is not associated with higher proliferative indices or with different expression of cell cycle inhibitors.