[955] Endosalpingiosis in Ovarian Serous Tumors of Low Malignant Potential

S Clement-Kruzel, A Malpica, B Djordjevic. University of Texas Houston Medical School, Houston, TX; M.D. Anderson Cancer Center, Houston, TX

Background: It has been suggested that a certain proportion of serous tumors of low malignant potential (SLMP) may arise from endosalpingiosis, and that endosalpingiosis may be the progenitor lesion in a proportion of non-invasive peritoneal implants as well as in some SLMP proliferations in lymph nodes. The objective of this study was to examine the rate of endosalpingiosis in nodal and extranodal tissue ovarian SLMP (OSLMP) cases relative other types of Mullerian malignancies.
Design: Thirty cases of ovarian serous tumors of low malignant potential with at least two lymph node sites and two peritoneal sampling sites were randomly selected from our institutional database. Two separate control groups consisting of thirty cases of radical hysterectomy cases for cervical adenocarcinoma and thirty total hysterectomy cases for endometrial endometrioid carcinoma were retrieved and matched to the experimental group based on the year of tumor diagnosis. All cases in each control group contained at least two lymph node sites and two peritoneal sampling sites. The number of lymph node sites and peritoneal sampling sites was recorded for the study group and each of the control groups. The statistical comparison between the study group and each of the control groups was made using the two-tailed Fisher exact test.
Results: The average number of lymph node sites examined was 3.5 for OSLMP, 4.1 for cervical adenocarcinoma, and 4.2 for endometrial carcinoma. The average number of peritoneal sampling sites was 5.9 for OSLMP, 3.8 for cervical adenocarcinoma, and 3.7 for endometrial carcinoma. Nodal endosalpingiosis was present in 30% of OSLMP cases, compared with 0% in cervical adenocarcinoma (p=0.0026) and 3% in endometrial carcinoma (p=0.0056). Five of the thirty OSLMP cases also showed lymph node involvement by SLMP. Extralymphatic endosalpingiosis was identified in 40% of OSLMP cases compared with 13% in cervical adenocarcinoma (p=0.0011) and 3% in endometrial carcinoma (p=0.0391).
Conclusions: The incidence of endosalpingiosis in OSLMP in extranodal tissue and lymph nodes is significantly greater than that found in matched cases of both cervical adenocarcinoma and endometrial carcinoma. This is the first study to document the relative incidence of endosalpingiosis in OSLMP compared to other types of Mullerian malignancies and it raises the question of whether endosalpingiosis should be considered a risk factor for the development of SLMP tumors.
Category: Gynecologic

Wednesday, March 11, 2009 9:30 AM

Poster Session V # 132, Wednesday Morning