Differentiation of ovarian mucinous carcinoma and metastatic colorectal adenocarcinoma by immunostaining with β-catenin

• Published in: Histopathology 2003-08, Vol.43 (2), p.151-156
• Main Authors: Chou, Y-Y, Jeng, Y-M, Kao, H-L, Chen, T- J, Mao, T-L, Lin, M-C
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - diagnosis; Adenocarcinoma - metabolism; Adenocarcinoma - secondary; Adenocarcinoma, Mucinous - diagnosis; Adenocarcinoma, Mucinous - metabolism; Adenocarcinoma, Mucinous - pathology; Atherosclerosis (general aspects, experimental research); beta Catenin; Biological and medical sciences; Biomarkers, Tumor - metabolism; Blood and lymphatic vessels; carcinoembryonic antigen; Cardiology. Vascular system; Cell Nucleus - metabolism; Cell Nucleus - pathology; colorectal cancer; Colorectal Neoplasms - diagnosis; Colorectal Neoplasms - metabolism; Colorectal Neoplasms - pathology; cytokeratin 20; cytokeratin 7; Cytoskeletal Proteins - metabolism; Diagnosis, Differential; Female; Female genital diseases; Gynecology. Andrology. Obstetrics; Humans; Immunoenzyme Techniques; immunohistochemistry; Medical sciences; ovarian mucinous carcinoma; Ovarian Neoplasms - diagnosis; Ovarian Neoplasms - metabolism; Ovarian Neoplasms - secondary; Trans-Activators - metabolism; Tumors; β-catenin
• ISSN: 0309-0167; 1365-2559
• DOI: 10.1046/j.1365-2559.2003.01687.x

Aims:  To investigate whether localization of β‐catenin is helpful in differentiating primary ovarian mucinous carcinoma and colorectal adenocarcinoma metastatic to the ovary. Extra‐ovarian cancers which metastasize to the ovaries, especially from colorectal adenocarcinoma, frequently mimic primary ovarian carcinomas, particularly endometrioid and mucinous types. Distinguishing primary ovarian carcinoma from metastatic colorectal carcinoma is important for both therapeutic and prognostic reasons. Even after thorough histological examination, metastatic colorectal adenocarcinomas are still often mistaken for primary ovarian adenocarcinomas. Although some tumour makers have been advocated and are helpful in most cases, sometimes the distinction between primary mucinous carcinoma and metastatic colorectal carcinoma remains a problem. Activation of Wnt signalling through mutations of APC or β‐catenin is a key event in the development of colorectal cancer. These mutations lead to nuclear localization of β‐catenin, which can be demonstrated immunohistochemically. Methods and results:  Formalin‐fixed paraffin‐embedded specimens from 43 primary ovarian mucinous carcinomas and 23 metastatic colorectal adenocarcinomas were included in this study. Sections were immunostained with antibodies to β‐catenin, cytokeratin (CK)7, CK20 and carcinoembryonic antigen (CEA). Nuclear localization of β‐catenin was found in 83% (19/23) of metastatic colorectal cancers and 9% (4/43) of ovarian mucinous carcinomas. Ovarian mucinous carcinomas were usually positive for CK7 (34/43, 79%). For comparison, 40 non‐mucinous carcinomas of the ovary and 42 metastatic adenocarcinomas from other organs were also immunostained with antibodies against β‐catenin. Although nuclear localization of β‐catenin was occasionally seen in non‐mucinous carcinoma of the ovary and metastatic adenocarcinoma from other organs, such tumours were usually distinguishable by their clinicopathological picture and rarely raised diagnostic problems. Conclusions:  Immunostaining of β‐catenin is a useful marker for differentiating between ovarian mucinous carcinoma and metastatic colorectal adenocarcinoma.