Small intestinal adenocarcinoma: cytokeratins 7 and 20

Normal small intestinal epithelium, like that of the large intestine, is strongly and diffusely positive for CK20 but negative for CK7. When an adenomatous component is present, it shows the same profile as the invasive component:

CK7

CK20

number of cases

24 (duodenum: 2, jejunum: 15, ileum: 7)¹, 23 (duodenum: 14, jejunum and ileum: 9, using tissue microarray)²

negative (<10%of cells)

0/24¹, 15/23²

8/24¹, 12/23²

10-25% of cells

5/24¹

2/24¹

26-50% of cells

6/24¹

6/24¹

>50% of cells

13/24¹

8/24¹

positive, NOS

8/23²

11/23²

This difference in cytokeratin profile between small and large intestinal adenocarcinomas is surprising. P504S may also be helpful in differentiating small from large intestinal adenocarcinomas.

References

¹Chen, Z. M. and H. L. Wang (2004). "Alteration of cytokeratin 7 and cytokeratin 20 expression profile is uniquely associated with tumorigenesis of primary adenocarcinoma of the small intestine." Am J Surg Pathol 28(10): 1352-9.

²Lee, M. J., H. S. Lee, et al. (2003). "Expression of mucins and cytokeratins in primary carcinomas of the digestive system." Mod Pathol 16(5): 403-10.

This page last revised 12.11.2004.

	CK7	CK20
number of cases	24 (duodenum: 2, jejunum: 15, ileum: 7)¹, 23 (duodenum: 14, jejunum and ileum: 9, using tissue microarray)²
negative (<10%of cells)	0/24¹, 15/23²	8/24¹, 12/23²
10-25% of cells	5/24¹	2/24¹
26-50% of cells	6/24¹	6/24¹
>50% of cells	13/24¹	8/24¹
positive, NOS	8/23²	11/23²