[1090] Immunohistochemical Expression of Two Upper Gastrointestinal (GI) Markers (CK17 and DPC4) in Primary and Metastatic Mucinous Ovarian Neoplasms.

Joshua M Lloyd, Alyssa M Krasinskas, Mamatha Chivukula. UPMC, Pittsburgh, PA

Background: In mucinous neoplasms of ovary, diagnosing metastatic disease can be challenging, especially in the setting of an occult primary. Morphologic and immunohistochemical parameters exist to aid in this distinction; however, they are not entirely specific. Cytokeratin (CK) 17 is a basal-type cytokeratin expressed in pancreaticobiliary carcinomas, whereas DPC4 (SMAD4) is a tumor suppressor that is inactivated in up to 40% of pancreatic adenocarcinomas. This study aims to determine the expression of CK17 and DPC4 in primary and metastatic mucinous ovarian tumors.
Design: DPC4 and CK17 expression were determined by immunohistochemistry (IHC) on primary low malignant potential (LMP) and invasive ovarian mucinous tumors (IMT-O), and metastatic mucinous ovarian tumors (MMT-O) (upper gastrointestinal in origin). Primary cholangiocarcinomas (CC), primary breast mucinous carcinomas (MT-B), and primary pancreatic neoplasms (PMT) were also stained. The intensity of staining (IS) was graded as negative-0, weak-1, moderate-2, and strong-3, and the proportion of positive staining cells (PS) was recorded as none (0), 1-5% (1), 6-20% (2), 21-80% (3), and 81-100% (4). A cumulative score (CS) was derived from PS and IS, and ranged from 0 to 7. CS was divided into negative (0), weak (1-2), moderate (3-5), and strong (6-7).
Results:

DPC4 (SMAD4) N(%)				Cytokeratin 17 N(%)
Cumulative Score (CS)	Negative/weak (0-2)	Moderate (3-5)	Strong (6-7)	Negative/weak (0-2)	Moderate (3-5)	Strong (6-7)
LMP-O* (n=15)	0	4 (27)	11 (73)	4/13 (31)	9/13 (69)	0
IMT-O (n=19)	0	6 (32)	13 (68)	9 (47)	9 (47)	1 (5)
MMT-O (n=12)	2 (17)	1 (8)	9 (75)	6 (50)	3 (25)	3 (25)
MT-B (n=13)	0	1 (8)	12 (92)	13 (100)	0	0
Primary CC* (n=30)	26 (87)	4 (13)	0	9/16 (56)	5/16 (31)	2/16 (13)
PMT* (n=10 )	3 (30)	2 (20)	5 (50)	2/9 (22)	4/9 (44)	3/9 (33)

*Cytokeratin 17 was performed on a subset of cases.


Conclusions: 1. Moderate-strong DPC4 expression is seen in primary LMP and invasive mucinous carcinomas. 2. Our study is the first to evaluate CK17 in ovarian neoplasms; moderate staining is seen in more than half of primary ovarian LMP and invasive mucinous tumors. 3. All primary mucinous carcinomas of breast demonstrate strong DPC4 expression (100%) and all are negative for CK17. 4. Though metastatic tumors to ovary show stronger DPC4 than CK17 expression, in determining the origin of a mucinous tumor of ovary, a combination of both marker expression favors metastatic disease from a pancreaticobiliary primary over an ovarian or breast primary.
Category: Gynecologic & Obstetrics

Tuesday, March 1, 2011 1:00 PM

Poster Session IV # 119, Tuesday Afternoon