DIFFERENT TYPES OF SEROUS CA OF THE ENDOMETRIUM

In 1990, we reported cases of serous carcinoma in endometrial polyps. Since that time, I have come to believe that there are probably different types of serous carcinoma of the endometrium:

1- Pure serous carcinoma. This type is not very frequent; it is very aggressive, infiltrates the myometrium, and frequently metastasizes, mainly to lymph nodes.

2- Serous carcinoma mixed with endometrioid carcinoma. This is the most frequent type. Sometimes it is difficult to determine how extensive it is because the p53 stain is also positive in obvious endometrioid areas. This type invades the myometrium but is not as aggressive as pure serous carcinoma.

3- Serous carcinoma in endometrial polyps. This type is interesting because it usually does not invade the myometrium. But it is frequently associated with or precedes surface papillary serous carcinoma of the peritoneum. It is possible that the tumor involves only the surface of a polyp. And because of this, some people have designated this lesion as "Intraepithelial Carcinoma". This has been a terrible designation because, first of all, it does not recognize the tumor as serous and because the designation intraepithelial gives the false impression that because there is no invasion the prognosis is excellent. Proper follow-up shows that a good number of these patients recur with serous carcinoma in the peritoneum. Because of this, endometrial polyps in post menopausal patients should be submitted entirely. And we need to review them slowly, looking for small foci of serous carcinoma.

I hope that future research will confirm or disprove the idea that there are probably different types of serous carcinoma of the endometrium, which raises important questions:

A- In mixed cases, is the endometrioid the first lesion, or do they start together? We have an idea of how endometrioid tumors develop, but not of how serous tumors develop.

B- Is the surface papillary serous carcinoma associated with serous carcinoma in polyps a multicentric disease? Obviouslly the different types would need different follow-up.