[1104] A Panel of Immunohistochemical Markers To Distinguish Ovarian from Uterine Serous Papillary Carcinomas

Y Zhang, MT Garcia, T Koru-Sengul, P Ganjei-Azar. University of Miami - Jackson Memorial Hospital, Miami, FL; University of Miami - Sylvester Comprehensive Cancer Center, Miami, FL

Background: Serous papillary carcinomas (SPC) have similar morphology whether they originated from ovary or uterus. When carcinomas are detected early, it is relatively easy to recognize the primary site. However, identification of the site of origin can be difficult once these tumors extend out of primary site or metastasize. Recognition of the site of origin influences the staging, management and prognosis of these malignancies. The purpose of this study is to identify a panel of markers to distinguish between ovarian and uterine primaries.
Design: Surgical specimens from 47 cases of SPC (33 uterine, 14 ovarian) were retrieved from the files. Hematoxylin&Eosin-stained slides were reviewed to confirm the diagnosis. Regardless of the histologic grade of the tumors, only sections with papillary growth pattern were selected for this study. Tissue sections were immunostained using antibodies for ER (1D5, Dako,1:10), p53 (Calbiochem, 1:250), WT1(Santa Cruz,1:200), IMP3(Dako,1:25), and P16 (Vision Biosystem,1:20). Cases were scored based on the percentage of positive cells: 0 (negative staining), 1 (focal, less than 50% of positive cells), and 2 (diffuse, more than 50% of positive cells). ER and p53 showed only nuclear staining. IMP3, WT1 and P16 showed strong cytoplasmic staining.
Results: Ovarian SPC expressed ER (92%), p53(92%), WT1 (100%), IMP3 (92%), and P16 (92%). Uterine SPC expressed ER (30%), p53(64%), WT1 (64%), IMP3 (85%), and P16 (76%). Ninety two percent of ovarian SPC had ER+WT1+ immunophenotype, whereas only 18% of the uterine SPC had the same immunophenotype. Seventy one percent of ovarian SPC had ER+ p53+ WT1+ IMP3+ P16+, whereas only 6% of the uterine SPC expressed this immunophenotype.

Table 1. Immunohistochemical Panel Used to Differentiate Ovarian vs. Uterine SPC

	ER+*	p53+	WT1+	IMP3+	P16+	ER+WT1+*	ALL markers +*
Ovarian SPC	92%	92%	100%	92%	92%	92%	71%
Uterine SPC	30%	64%	64%	85%	76%	18%	6%

* (p < 0.001)


Conclusions: A panel of ER+, WT1+, p53+, IMP3+ and P16 +immunohistochemical markers favors an ovarian origin and potentially may distinguish these tumors from metastatic uterine SPC (p<0.001). ER was expressed in most ovarian SPC whereas majority of uterine primaries were negative.
Category: Gynecologic

Wednesday, March 11, 2009 9:30 AM

Poster Session V # 138, Wednesday Morning