Immunophenotyping of Intestinal Type of Cervical Adenocarcinoma
RS Saad, M Xu, N Ismiil, S Nofech-Mozes, V Dube, Z Ghorab, MA Khalifa. Sunnybrook Health Science Center, Toronto, ON, Canada
Background: Immunohistochemistry plays a critical role in identifying the primary site of metastatic tumors with unknown origin. Although CDX-2 is considered a specific and sensitive marker for colorectal carcinoma, some studies have shown its expression in other carcinomas with intestinal differentiation. There is limited data about its expression in cervical adenocarcinoma. In this study, we investigated the expression of CK7, CK20, CDX-2 and p16 in different types of cervical adenocarcinomas.
Design: Seventy specimens of cervical adenocarcinoma were retrieved from the archives of anatomic pathology, including 30 usual (endocervical), 26 intestinal, 6 endometrioid and 8 mixed types. All cases were stained for CK7, CK20, CDX-2 and p16. Staining was considered positive when it was cytoplasmic for CK7 and CK20, nuclear for CDX-2 and both nuclear and cytoplasmic for p16. Percentage of cells staining was recorded as follow: Negative (0-5%), weak 1+, 6-25%), moderate (2+, 26-50%), and strong (3+, >50%). Fifty cases of rectal adenocarcinoma were included as a control group.
Results: Adenocarcinoma in situ was seen in 51/70 (73%) of cases and their results were comparable to their invasive counterparts. CK7+/CK20+ immunophenotype was expressed in 10% of usual type, 46% of intestinal type, 38% of mixed type and none of endometrioid type. In rectal adenocarcinoma, CK7+/CK20+ immunophenotype was expressed in 10/50 (20%) of the cases; however, CK7 was focal (6-25%) in 6 of these cases. Three cases were negative for CK7/CK20 (6%).
|Usual (30 cases)||30/30 (100%)||3/30 (10%)||6/30 (20%)||30/30 (100%)|
|Intestinal (26 cases)||26/26 (100%)||10/26 (46%)||21/26 (81%)||25/26 (96%)|
|Endometrioid (6 cases)||5/6 (83%)||0/6 (0%)||1/6 (17%)||5/6 (83%)|
|Mixed type||8/8 (100%)||3/8 (38%)||3/8 (38%)||8/8 (100%)|
|Rectal group (50 cases)||10/50 (20%)||47/50 (94%)||50/50 (100%)||7/50 (14%,Focal)|
Conclusions: CDX-2 was expressed in the majority of endocervical adenocarcinoma, intestinal type. Therefore, CDX-2 is a marker for intestinal differentiation and should not be used as the sole basis for confirming the colorectum as the primary origin for metastatic cases. Although there is immunophenotypic overlap, diffuse staining for CK7 and p16 helps distinguish cervical from rectal adenocarcinomas. CK20+/CK7- immunophenotype is more specific in predicting the colorectal origin than CDX-2 expression alone.
Monday, March 9, 2009 1:00 PM
Poster Session II # 146, Monday Afternoon