[1234] Serous Tumor of Low Malignant Potential of the Ovary – Is the 10% Cut-Off Reliable?

Preetha Ramalingam, Michael T Deavers, Anais Malpica. MD Anderson Cancer Center, Houston

Background: Conventionally, ovarian serous neoplasms of low malignant potential (OV-SLMP) are diagnosed when epithelial proliferation and detached cell clusters are present in ≥10% of the tumor. Some authors have suggested the terms "focal proliferation" or "focally atypical" when the epithelial proliferation comprises <10% of an otherwise typical serous cystadenofibroma (SCA). Using these terms at frozen section (FS) does not typically prompt staging and the peritoneal cavity is left unexamined. However, we have encountered rare cases of SCA with <10% proliferation associated with non-invasive and/or invasive peritoneal implants (Ni-IM; I-IM). The aim of our study is to evaluate the incidence of extraovarian disease in cases of "focal OV-SLMP" and determine its correlation with clinical outcome.
Design: Cases of focal OV-SLMP were selected from a cohort of OV-SLMP from 1985-2006. Focal OV-SLMP is defined as epithelial proliferation and cell detachment, diagnostic of LMP, but present in <10% of the tumor. The presence of proliferation without cell detachment was designated as "focal proliferative areas". The following parameters were evaluated- age, size, laterality, status of the opposite ovary, pathologic staging (if performed), the presence of extraovarian disease (at time of presentation and subsequently) and clinical follow up.
Results: 1,123 OV-SLMP were identified, of these 20 (1.8%) met criteria for focal OV-SLMP. Patients were 32-81yrs (median 62.5); 14 (70%) were post-menopausal (PM). Ovarian size was 1.2-18cm (7.9cm mean); laterality was: left (10), right (9) and bilateral (1). External surface of ovary was smooth (18), granular (1) and not known (NK) in 1 case. The cyst wall was smooth (11), granular (4), had focal papillary excrescences (4) or NK (1). Opposite ovary had endosalpingiosis (3), SCA (9), SCA with focal proliferative areas (2), focal OV-SLMP (2), normal (1), NK (1), Sertoli Leydig cell tumor (1) not removed (1). Peritoneal sampling (n=14) revealed 2 cases with endosalpingiosis and implants (1 Ni-IM and 1 I-IM). 1 case developed SCA with focal proliferative areas and endosalpingiosis in the pelvis 5yrs later. Follow-up on 17 cases ranged from 60-138 mos (median 74mos). 15 pts. were alive with no evidence of disease, 1 pt. with I-IM died of disease, 1 pt. was alive with cervical cancer.
Conclusions: Extraovarian disease in focal OV-SLMP is rare and appears to be associated with endosalpingiosis. Although rare, it can result in an unfavorable outcome depending on the nature of the implants. Focal OV-SLMP, if identified at FS should prompt examination of the peritoneal cavity, particularly in PM women.
Category: Gynecologic & Obstetrics

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 190, Tuesday Morning


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