[1235] SALL4, Glypican-3 and CDX2 Expression in Endometrial Endometrioid Adenocarcinomas: An Immunohistochemical Study of 57 Cases

Preetha Ramalingam, Ramya P Masand, Anais Malpica. UT MD Anderson Cancer Center, Houston

Background: Yolk sac tumor (YST) can share histological features with endometrioid carcinoma which can pose a diagnostic challenge. This is especially true in cases of YST at unusual anatomical sites such as the endometrium. SALL4, glypican-3, and CDX2 are known to be expressed in ovarian YSTs. While CDX2 has been found to be expressed in the squamous morules of endometrial endometrioid proliferations, the other two markers have not been evaluated in endometrial endometrioid adenocarcinomas. In this study we evaluate the expression of SALL4, glypican-3, and CDX2 in endometrial endometrioid adenocarcinomas.
Design: Fifty-seven cases of endometrial endometrioid adenocarcinomas (FIGO grades: 1, 2 and 3) were retrieved from the pathology files of our institution covering a period of 15 years (1996 to the present). All the cases were stained for SALL4 (6E3, 1:100, Biocare Medical, Concord, CA), glypican-3 (1G12, predilute, Cell Marque, Rocklin, CA), and CDX2 (CDX2-88, 1:50, BioGenex, Freemont, CA). Granular cytoplasmic staining for glypican-3, and nuclear staining for SALL4 and CDX2 were interpreted as positive. Staining in the glandular component of the neoplastic cells was graded as follows: 0: no detectable staining, 1+: 1-5%, 2+: 6 to 25%, 3+: 26 to 50%, 4+: 51 to 75% and 5+: >76%. For grading of CDX2, staining in the squamous morular component was excluded.
Results: Of the 57 endometrial endometrioid adenocarcinomas, only 2 showed 1+ staining for SALL4, while 55 (96%) were negative. Of the glypican-3 cases 6 showed 1+ staining, 1 showed 3+ staining, 48 were negative and 2 cases had excessive background staining and were not interpretable. Staining for CDX2 in the glandular component of the tumors was 1+ in 9 cases and 48 cases were negative. CDX2 staining exclusively in squamous morules was observed in 8 cases and were included in the negative group.
Conclusions: SALL4 is a reliable immunohistochemical marker to distinguish YST from endometrial endometrioid adenocarcinoma, as it is positive in less than 5% of the latter. Glypican-3 also appears to be a useful marker for this distinction, however, a rare case of endometrial endometrioid adenocarcinoma can show diffuse staining for glypican-3. As expected, we found that CDX2 was strongly positive in squamous morules, and was also focally expressed in the glandular component of endometrial endometrioid adenocarcinoma, in up to 15% of the cases.
Category: Gynecologic & Obstetrics

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 202, Wednesday Afternoon


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