• All IHC stains will include a positive control tissue

• This marker may be used to confirm hairy cell leukemia in decalcified bone marrow trephines (formalin or B+ fixation). VE-1 positivity distinguishes hairy cell leukemia from splenic marginal zone lymphoma, hairy cell leukemia variant, and other low-grade B-cell lymphoproliferative disorders mimicking hairy cell leukemia
• This test may be used in an algorithm in the evaluation of colorectal carcinomas, along with MMR IHC evaluation
• Negative cases should be sent for MLH1 promoter hyper-methylation, similar to a negative BRAF molecular result.
• Equivocal cases should be sent for BRAF molecular
• Concordance between IHC and DNA sequencing for BRAF has been reported to be 96.7% (266/275 cases) according to a white paper from Dvorak, PhD Ventana Medical Systems; 98.2% of cases (162/165) that were negative for BRAF by IHC were negative by sequencing and 94.5% of cases (104/110) that were positive for BRAF by IHC were confirmed by sequencing
• Recent studies have found a very high (>95%) concordance between IHC using the VE1 antibody and the presence of BRAFV600E in HCL as well as other non-lymphoid cancers
• BRAF mutations have also been reported in most pleomorphic xanthoastrocytomas (PXA)

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

• This antibody is used to identify the mutant protein, BRAF V600E
• BRAF mutations have been identified in approximately 8% of all solid tumors, including 43% of melanomas, 39% of papillary thyroid carcinomas, 12% of serous ovarian carcinomas, 12% of colorectal adenocarcinomas, and 2% of lung and other cancers
• Sporadic colorectal carcinomas are caused by 2 primary carcinogenesis pathways, the adenoma-adenocarcinoma sequence, in which cancers arise from tubular adenomas, and the serrated neoplasia pathway, in which cancers arise from serrated polyps
• The serrated pathway is distinct from the conventional adenoma-adenocarcinoma pathway, given that the former demonstrates unique genetic alterations, such as the BRAF mutation, DNA hyper-methylation, and microsatellite instability
• BRAF mutations have been observed in 22 of the 28 (78.6%) serrated adenoma cases ¹, and all BRAF mutations occurred in the tall cells
• Recent studies have shown that BRAF IHC is highly concordant with PCR based assays and has a lower failure rate than PCR assays
• Among B-cell lymphomas, the presence of the BRAF V600E mutation is nearly diagnostic for hairy cell leukemia and has therapeutic significance

 Staining patterns

• Cytoplasmic staining in BRAF mutated cancers in >75% of malignant cells (disregard nuclear or nucleolar staining)
• Occasional positive cases will show only weak but diffuse cytoplasmic staining (distinctive from nonspecific staining in non-neoplastic cells)
• Patchy nonspecific staining can be seen in smooth muscle cells, mucin, and non-neoplastic colonic mucosa (often with a nuclear pattern of staining)

References

1. Shi Y et al: Meriden Z et al: BRAF mutation is associated with the unique morphology of traditional serrated adenoma of the colorectum. International Journal of Surgical Pathology 21(5) 442-448, 2013.
2. White paper by Dvorak K: Evaluation of BRAF (V600E) mutation by immunohistochemical staining with anti-BRAF V600E(VE1) antibody: a comparison with sanger sequencing.
3. Ida CM et al: Immunohistochemistry is highly sensitive and specific for detection of BRAF V600E mutation in pleomorphic xanthoastrocytoma. Acta Neuropathologica Communications 2013, 1:20.
4. Kuan SF et al: Immunohistochemical detection of BRAF V600E mutant protein using the VE1 antibody in colorectal carcinoma is highly concordant with molecular testing but requires rigorous antibody optimization. Human Pathology (2014) 45, 464-472.
5. Toon CW et al: BRAFV600E Immunohistochemistry Facilitates Universal Screening of Colorectal Cancers for Lynch Syndrome. Am J Surg Pathol _ Volume 37, Number 10, October 2013.
6. Chappe C, Padovani L, Scavarda D, Forest F, Nanni-Metellus I, Loundou A, et al. Dysembryoplastic Neuroepithelial Tumors Share with Pleomorphic Xanthoastrocytomas and Gangliogliomas BRAF(V600E) Mutation and Expression. Brain pathology (Zurich, Switzerland). 2013;23(5):574-83.
7. Enrico Tiacci, M.D., Vladimir Trifonov, Ph.D., Gianluca Schiavoni, Ph.D., et al: BRAF Mutations in Hairy-Cell Leukemia. N Engl J Med 2011; 364:2305-2315. June 16, 2011
8. Luca Arcaini1, Silvia Zibellini1, Emanuela Boveri, et al: The BRAF V600E mutation in hairy cell leukemia and other mature B-cell neoplasms. Blood 2012; 119(1):188-191.