[1069] Is There an Association between the Micropapillary/Cribriform Pattern in Ovarian Serous Tumors of Low Malignant Potential and Microinvasion?

AA Roma, MT Deavers, A Malpica, EG Silva. Washington University in St Louis, St Louis, MO; M.D. Anderson Cancer Center, Houston, TX

Background: Microinvasion (Minv) has been found to occur in 53% of advanced stage Ovarian Serous Tumors of Low Malignant Potential (SLMP), classic type. However this histological finding has not been specifically studied in SLMP with micropapillary or cribriform pattern (MP/CP). The purpose of this study is to determine the incidence, histological characteristics, and significance of MInv in cases of advanced stage OSLMP with a MP/CP.
Design: H&E slides from 56 cases of advanced stage SLMP with MP/CP were retrieved from the files of our department. Minv was recognized as foci of individual cells, clusters of cells or papilla within the stroma, surrounded by clefts without epithelial lining, measuring up to 3 mm in a single dimension or 10 mm². The following parameters were recorded: percentage of MP/CP in the SLMP (< 10% and 10%), and size and number of the focus/foci of Minv. Follow-up (F/U) was obtained from the patients' charts. Chi-square was used to determine statistical significance (p<0.05).
Results:

In addition, cases of SLMP with <10% MP/CP had foci of Minv that were smaller (<1mm) but more abundant (up to 22 foci), while cases with 10% MP/CP contain foci of Minv that were larger (2mm) but less numerous (up to 4 foci). In 18 (86%) of 21 cases, the Minv foci were not underlying MP/CP areas.
Conclusions: 1 Minv is not associated with the presence or extent of MP/CP. 2 Minv is not commonly identified in areas of MP/CP (14%). 3 The frequency of Minv in cases with MP/CP (38%) is not statistically different from the frequency of Minv in previously reported cases of advanced stage SLMP, classic type (53%) (p=0.2). 4 Independent of the amount of MP/CP, the frequency of Minv did not adversely affect the prognosis of the pts (p=0.7). 5- Most probably two very important functions of the cells in serous borderline tumors, proliferation and invasion, are independent and follow different pathways.
Category: Gynecologic

Monday, March 9, 2009 1:00 PM

Platform Session: Section C, Monday Afternoon