• All IHC stains will include a positive control tissue

• Beta-catenin nuclear staining is seen in a very limited subset of mesenchymal tumor types, including desmoid-type fibromatosis (71% of cases), solitary fibrous tumor (40%), endometrial stromal sarcoma (40%) and synovial sarcoma (28%)
• Beta-catenin can be used to separate sclerosing mesenteritis and GIST from fibromatosis. In one study, beta-catenin detected in 9 of 10 fibromatoses, including one case associated with familial adenomatous polyposis; none of the sclerosing mesenteritis or GIST cases had nuclear catenin
• In patients with CUC, the combination of strong p53 expression and absent or weak beta catenin expression is evidence in favor of a CUC-associated polypoid dysplastic lesion in diagnostically difficult lesions
• Beta-catenin expression is seen in fibromatosis of the breast, and in the stromal component of phyllodes tumors
• Aberrant beta-catenin expression is often observed in metaplastic breast carcinomas
• Beta-catenin may be seen in high grade sarcomas, where it is thought to act as an oncoprotein with intracytoplasmic and nuclear localization with binding to nuclear DNA

Submit a formalin-fixed, paraffin embedded tissue block

Formalin-fixed, paraffin embedded (FFPE) tissue block

Tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• Beta-catenin is an intracellular protein that is regulated by the APC protein
• Mutations of either the APC gene or the beta-catenin gene can result in the nuclear accumulation of beta-catenin protein
• Fibromatoses typically have mutations in the APC/beta-catenin pathway and hence have abnormal nuclear accumulation of beta-catenin protein

 Staining patterns

• Strong nuclear staining with variable cytoplasmic staining

References:

1. Montgomery E et al: Beta-Catenin immunohistochemistry separates mesenteric fibromatosis from gastrointestinal stromal tumor and sclerosing mesenteritis. Am J Surg Pathol. 26(10): 1296-1301, 2002.
2. Walsh et al p53 and Beta catenin expression in chronic ulcerative colitis-associated polypoid dysplasia and sporadic adenomas: an immunohistochemical study. Am J Surg Pathol. August 1999 - Volume 23 - Issue 8 - p 963.
3. Geyer et al: Beta-Catenin pathway activation in breast cancer is associated with triple-negative phenotype but not with CTNNB1 mutation. Modern Pathology (2011) 24, 209-231.
4. Lacroix-Triki et al: Beta-catenin/Wnt signalling pathway in fibromatosis, metaplastic carcinomas and phyllodes tumours of the breast Modern Pathology (2010) 23, 1438-1448.
5. Kuhnen et al: Beta-catenin in soft tissue sarcomas: expression is related to proliferative activity in high-grade sarcomas. Mod Pathol 2000;13(9):1005-1013.
6. Ng TL, Gown, A et al: Nuclear beta-catenin in mesenchymal tumors. Modern Pathology (2005) 18, 68-74.