ROLE OF COMPUTED QUANTITATION OF IMMUNOHISTOCHEMICAL STAINING OF KI-67 ANTIGEN IN DIAGNOSING AMPULLARY LESIONS

OBJECTTVE: To determine the possible role of Ki-67 antigen expression by visual and computed quantitation in diagnosing ampullary lesions. S TUDY DESIGN: Twenty-two cases of ampullary lesions treated at Thomas J efferson University Hospital between 1989 and 1994 were analyzed. Four cases of adenoma, 4 of epithelial dysplasia in adenoma, 7 of well-dif ferentiated adenocarcinoma and 7 of high grade adenocarcinoma were inc luded. For each case three consecutive sections were obtained from the paraffin-embedded blocks. The first slide was stained with hematoxyli n & eosin for visual diagnosis; the other two were immunoprocessed to evaluate the expression of Ki-67 antigen. Visual quantitation of Ki-67 was evaluated by light microscopy, and computed quantitation was perf ormed utilizing the SAMBA 4000 cell image analysis system. RESULTS: Im munohistochemical analysis of the ampullary lesions showed a positive correlation of Ki-67 expression, both by visual and computed quantitat ion, with biologic grade. The cell proliferation sequence was carcinom a, adenoma with dysplasia and adenoma. CONCLUSION: Ki-67 antigen expre ssion correlated highly with the progression of malignancy in ampullar y lesions. Computed quantitation of Ki-67 was more sensitive than visu al quantitation, especially in differentiating between low and high gr ade adenocarcinomas.