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Int J Clin Exp Pathol 2013;6(4):630-638

Original Article
An immunohistochemical study of primary signet-ring cell carcinoma of the stomach and
colorectum: III. expressions of EMA, CEA, CA19-9, CDX-2, p53, Ki-67 antigen, TTF-1,
vimentin, and p63 in normal muco-sa and in 42 cases

Tadashi Terada

Departments of Pathology, Shizuoka City Shimizu Hospital, Shizuoka, Japan

Received January 7, 2013; Accepted February 16, 2013; Epub March 15, 2013; Published April 1, 2013

Abstract: There have no comprehensive immunohistochemical studies of primary signet ring cell carcinoma (SRCC) in the stomach and
colorectum. The author examined the expression of nine common antigens (EMA, CEA, CA19-9, CDX-2, p53, Ki-67 antigen, TTF-1, vimentin,
and p63) in the non-tumorous normal epithelium of the stomach and colorectum and in 42 cases of primary SRCC of the stomach (30 cases)
and colorectum (12 cases). The normal epithelium of the stomach and colon consistently (100%) expressed EMA, CEA, CA19-9, CDX-2, and Ki-
67 (labeling <15%). Normal epithelium of these locations never expressed p53, TTF-1, vimentin, and p63. In the primary gastric SRCC, the
expression percentage of EMA was 57% (17/30), CEA 100% (30/30), CA19-9 100% (30/30), CDX-2 43% (13/30), p53 83% (25/30), Ki-67 100%
(30/30) (labeling index= 36 ± 23 %), TTF-1 0% (0/30), vimentin 0% (0/30), and p63 0% (0/30). In primary colorectal SRCC, the expression
percentage of EMA was 25% (3/12), CEA 100% (12/12), CA19-9 100% (12/12), CDX-2 93% (28/30), p53 75% (9/12), Ki-67 100% (30/30)
(labeling index= 47% ± 26 %), TTF-1 0% (0/12), vimentin 0% (0/12), and p63 0% (0/12). A comparative statistical analysis showed significant
difference in EMA (gastric SRCC 57% vs colorectal SRCC 25%) and CDX-2 (43% vs 93%). There were no significant differences in the other
seven antigens’ expression between primary gastric SRCC and primary colorectal SRCC. These findings provide much knowledge of primary
SRCC of the stomach and colorectum. The data indicated primary gastric SRCC frequently express EMA but not CDX-2 whereas primary
colorectal SRCC frequently express CDX-2 but not EMA. These findings also suggest that EMA and CDX-2 are down-regulated during the
gastric SRCC carcinogenesis. This down regulations may be associated with the malignant transformation of gastric SRCC. The data of
colorectal SRCC suggest EMA is markedly down-regulated and also suggest that this EMA down-regulation may be associated with the
carcinogenesis of colorectal SRCC. The expression pattern of EMA and CDX-2 may be useful in differential diagnosis between primary gastric
SRCC and primary colorectal SRCC in the metastatic sites of SRCC. (IJCEP1301016).

Keywords: Signet-ring cell carcinoma, common antigens, EMA, CDX-2, stomach, colorectum, histopathology, immunohistochemistry

Address correspondence to: Dr. Tadashi Terada, Department of Pathology, Shizuoka City Shimizu Hospital, Miyakami 1231 Shimizu-Ku, Shi-
zuoka 424-8636, Japan. Tel: +81-54-336-1111; Fax: +81-54-334-1173; E-mail: piyo0111jp@yahoo.co.jp