[1045] The Accuracy of an Intraoperative Diagnosis of Ovarian Borderline Tumor Varies by Histologic Subtype.

Karuna Garg, Karin Shih, Richard Barakat, Nadeem Abu-Rustum, Robert A Soslow. MSKCC, New York

Background: Borderline (BT) ovarian tumors are treated differently depending on the surgeon, patient age, the type of borderline tumor and co- morbid conditions. When the tumor appears to be confined to the ovary, these patients typically undergo conservative surgery. To determine whether additional surgery is needed in this situation, it becomes important to understand the extent to which frozen section diagnoses are overturned on review of permanent sections. The purpose of this study was to assess the sensitivity and positive predictive value of an intraoperative ovarian borderline tumor diagnosis at our institution.
Design: All patients with an intraoperative or final pathologic diagnosis of ovarian borderline tumor of all histologic subtypes between years 2000 to 2010 were included in the study.
Results: A total of 166 patients were included in the study. The median age was 49 years (20.3-91.2 yrs). The sensitivity and positive predictive value of an intraoperative diagnosis of ovarian borderline tumor was 81.6% and 89.9% respectively. 75% of tumors diagnosed as borderline on frozen retained this diagnosis at final pathology (74.6%) while 14 (8.4%) were upgraded from borderline to carcinoma. Twenty cases diagnosed as benign on frozen were upgraded to borderline (12%), while 8 cases (5%) were downgraded from carcinoma to borderline. The rates of undercalling carcinoma as borderline tumor on frozen section varied considerable by histologic type: 5% of tumors diagnosed as serous BTs, 0% of seromucinous BTs, 14% of intestinal mucinous BTs and 80% of small numbers of endometrioid BTs were reclassified as carcinomas on permanent sections. Most under calls were due to sampling error, not interpretive error. Further study of the serous tumors revealed differences related to the presence of micropapillary architecture, with 21% of tumors diagnosed as micropapillary serous BTs reclassified as carcinomas on permanent section compared to 1% of non-micropapillary serous BTs.
Conclusions: One can anticipate an accurate frozen section diagnosis of BT when the tumor is serous or seromucinous and non-micropapillary. This does not provide unmitigated support for performing staging surgeries for these types of borderline tumors when disease appears clinically confined to the ovary, without surface involvement. Significant rates of underdiagnosis can be anticipated with micropapillary serous, intestinal mucinous and endometrioid tumors when diagnosed as BT on frozen section. This provides sufficient support for performing cancer-type staging surgeries at the discretion of the surgeon in these circumstances.
Category: Gynecologic & Obstetrics

Monday, February 28, 2011 8:00 AM

Platform Session: Section D, Monday Morning

 

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