[1104] Tumor Progression from Ovarian Endometriotic Cyst to Endocervical-Like (Mullerian-Seromucinous) Tumors: Immunohistochemical Comparison of Endometriotic Cyst and the Neoplasm

Ayse Ayhan, Hiroshi Ogawa, Tamer Seckin, Elisabetta Kuhn, Tsui-Lien Mao, Naveena Singh, Robert J Kurman, Ie-Ming Shih. Johns Hopkins Medical Institutions, Baltimore, MD; Seirei Mikatahara General Hospital, Hamamatsu, Japan; National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei, Taiwan; North Shore LIJ-Lenox Hill Hospital, New York, NY; Barts and the London NHS Trust, London, United Kingdom

Background: Non-gastrointestinal, endocervical-like, Mullerian mucinous tumor of the ovary which has different clinicopathological and immunophenotypical characteristics from other mucinous ovarian tumors is characterized by higher frequency of bilaterality and hormone receptor reactivity. This tumor is also named “seromucinous neoplasm” due to its macroscopical and structural mimicry to ovarian serous tumors while histologically composed mostly of endocervical type mucinous epithelial cells, often admixed with various Mullerian-type epithelia. As its association with endometriosis is typical and endometriosis is thought to be a precursor of this neoplasm; we undertook an immunohistochemical analysis to compare the properties of endometriotic cyst with the neoplastic cells for aiding the classification, terminology and tumorigenesis.
Design: Our immunohistochemical study set consisted of 14 endocervical-like mucinous borderline tumors from 10 patients, out of which 10 tumors were in continuity with an endometriotic cyst. Immunohistochemical features of neoplastic cells were compared to endometriotic cyst for hormone receptors (ER, PgR), ARID1A, PTEN tumor suppressors, p21, WT-1, PAired –boX2 and 8 products which were major players in development, organogenesis and cell-lineage determination.
Results: Bilateral tumors showed similar immunophenotype and counted as one. Endometriotic epithelium and its non-neoplastic nature was confirmed by CD10, p53 and Ki67(MIB-1). WT-1, PAX2, PAX8, p21 and PgR were concordantly downregulated in endometriotic epithelium while strongly positive in tumor cells in 70% of cases. On the other hand, ARID1A and PTEN loss was observed concomittently in 1(10%) case where p21 was particularly positive in the endometriotic cyst and WT-1 was not expressed in tumor cells. ER did not show any particular difference between the tumor and the endometriotic cyst.
Conclusions: Our study suggest that endocervical-like (Mullerian-seromucinous) tumors have distinct immunophenotypical properties and it should be a unique additional tumor type arising in endometriosis.
Category: Gynecologic & Obstetrics

Wednesday, March 6, 2013 9:30 AM

Poster Session V # 184, Wednesday Morning


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