Immunohistochemical expression of cytokeratin 7 and cytokeratin 20 in ovarian and gastrointestinal carcinoma

Abstract EN

Background : Among the most common carcinomas metastatic to the ovary that mimic ovarian primary are gastrointestinal tract (GIT) carcinomas.

The histologic distinction between them can be difficult.

Material and Method : In an effort to facilitate this distinction we have evaluated the use of immunohistochemical techniques with antibodies to cytokeratin 7 and 20.

We studied 86 cases of multiple ovarian tumors and primary GIT tumors likely to metastasize to the ovary, these included 32 cases of primary colorectal carcinoma and 27 cases of primary ovarian carcinoma, 10cases of gastric carcinoma, 5 cases of pancreatic carcinoma and 12 cases of metastatic ovarian carcinoma (4 colonic and 8 gastric).

Result : It was found that no cases of colonic carcinoma whether primary or metastatic exhibits CK7 + / CK20-.

So ovarian tumors exhibiting this pattern is almost certainly not of colonic origin, however distinguishing upper GIT (gastric or pancreatic) from ovarian tumor based on this pattern is unreliable as definite number of upper gastrointestinal tract carcinomas whether gastric or pancreatic were CK7 + / CK20-(50 %, 80 % respectively).

CK7- / CK 20 + pattern was highly suspicious for tumors for colonic origin, while only 50 % of rectal carcinomas have this pattern.

Dual positive CK7 + / CK20 + were relatively uncommon, it represents 45 %, 10 % and 25 % in ovarian mucinous, colonic and rectal carcinomas respectively.

The least dual negative CK7- / CK20- pattern was rare in colonic carcinoma (20 %) and absent in ovarian carcinoma.

Conclusion : Immunohistochemical pannel using CK7and CK20 is very helpful in determining the colonic origin of tumors metastasizing to the ovary.