Recurrence in noninvasive endometrial carcinoma. Relationship to uterine papillary serous carcinoma

In a series of 227 consecutive operable clinical stage I endometrial carcinomas, there were 28 recurrences. In seven of these cases, no myometrial or vascular invasion was demonstrable. Recurrence in these seven noninvasive cases was strongly associated with papillary serous carcinoma, even when present only focally or manifested by typical cytological features in the absence of well-formed papillae. An association with foci of clear cell carcinoma was also seen, as was direct evidence in two cases of synchronous ovarian serous carcinoma, one in situ.