Lymph Node Involvement in Ovarian Serous Tumors of Low Malignant Potential
B Djordjevic, A Malpica. M.D. Anderson Cancer Center, Houston, TX
Background: Lymph node involvement (LNI) in ovarian serous tumors of low malignant potential (OSLMP) has been reported in 21% to 42% of OSLMP. However, there is still limited experience with the clinical significance of LNI as well as with the variety of histologic patterns of LNI.
Design: 28 cases of OSLMP with LNI with available slides were retrieved from our files. A control group of 28 OSLMP with at least two sites of lymph node resection and no LNI was established by matching the year of diagnosis for each study case. Clinical follow-up was obtained from review of the medical records and from phone calls to the attending physicians. The pathologic features recorded included microinvasion and micropapillary/cribriform (MP/CP) pattern in the OSLMP and invasive and non invasive implants. The histologic features of LNI recorded were pattern (single cells, clusters, micropapillae, small papillae, papillae, glandular and intraglandular), location (subcapsular, medullary, parenchymal, lymphatics within the capsule) and endosalpingiosis. Statistical comparisons were made using the Fisher exact test.
Results: The mean patient age in the study group was 39.2 and 49.0 in the control group. Differences in microinvasion, MP/CP pattern, invasive and non invasive implants between the study and the control group were not statistically significant. However, OSLMP cases with LNI had 50% rate of endosalpingiosis compared to only 17% in the control group (p=0.0227). The average number of lymph node sites harvested was comparable between the study (3.81) and the control group (3.63). In 18% of cases in the study group LNI represented the only site of extraovarian disease. LNI displayed a combination of patterns in 82% of cases, with single cells being the most frequent pattern (64%) and occurring in the subcapsular location (83%). The intraglandular pattern was observed in 32% of the cases, and was the sole pattern in 33% of this subset. 89% of cases with the intraglandular pattern were associated with endosalpingiosis and 100% had a parenchymal location. Follow-up was available for 86% of the cases in both groups. The difference in overall survival was not statistically significant (p=0.1085).
Conclusions: Patients with OSLMP with LNI are on average 10 years younger and in 18% of cases LNI was the only indication of extraovarian disease, highlighting a need for staging in all OSLMP surgeries. The pattern of LNI seems to be single cell-related or endosalpingiosis-related. The pathogenetic and prognostic significance of these LNI patterns merits future investigation.
Monday, March 9, 2009 9:30 AM
Poster Session I Stowell-Orbison/Autopsy Award # 146, Monday Morning