To the Editors
We read with great interest the contribution by Dr. Terada T regarding the study, entitled “Hepatocellular carcinoma metastatic to the gingiva as a first manifestation of hepatocellular carcinoma” [1]. The author presented a good case report, and implemented a comprehensive discussion. However, there was a typo in the “Abstract” section that CAM5.2 was misspelled “CAM6.2”. Additionally, this article contains a wrong identification in the second paragraph of the “Case Report” section that I believe, may misguide the readers. Dr. Terada T may have inadvertently annotated that “CAM5.2 reacted with both cytokeratin 8 and 18”.
We would like to explain that the anti-cytokeratin CAM 5.2, clone CAM 5.2, is marketed by Becton–Dickinson Biosciences (Franklin Lakes, NJ). This clone primarily recognizes both human cytokeratin proteins 7 and 8, whereas it is lesser specific to cytokeratin 7. Both peptides are found in most epithelial cells, with the exception of stratified squamous epithelium [2].
As a result, it is clarified that anti-cytokeratin CAM5.2 monoclonal antibody is a marker for cytokeratin 7 and 8 but not for cytokeratin 18. This letter can help us elucidate the critical points that CK8/18 is not equivalent to CAM5.2; as well as anticytokeratin CAM5.2 should not be mistaken for monoclonal antibody CK8/18 [2, 3]. However, this finding does not detract from the study results and impressions that hepatocyte paraffin-1 (HepPar-1) (OCH1E5, Dako) is a relatively specific marker of hepatocytes and hepatocellular carcinoma. Hepatocellular carcinoma can manifest as small gingival tumors, and careful hematoxylin-eosin stain and immunoreactive HepPar-1 are useful in the diagnosis of hepatocellular carcinoma in extrahepatic metastatic sites [1].
Conflict of Interests
None.
References
- 1.Terada T (2011) Hepatocellular carcinoma metastatic to the gingiva as a first manifestation of hepatocellular carcinoma. J Maxillofac Oral Surg (JMOSI). doi: 10.1007/s12663-011-0187-z [DOI] [PMC free article] [PubMed]
- 2.BD Biosciences anti-cytokeratin (CAM 5.2) reagent for in vitro diagnostic use: 50 tests per vial—catalog no. 349205. Data sheet, Available at: http://www.bdbiosciences.com/external_files/is/doc/tds/Package_Inserts_IVD/live/web_enabled/23-3190-02%20PI_Anti-Cytokeratin_IVD_EN.pdf and http://www.bdbiosciences.com/external_files/is/doc/tds/Datasheets_RUO/live/web_enabled/23-1336-09-347653-347204-349205-DS-ruo.pdf. Accessed 03 July 2011
- 3.Leica Microsystems. Novocastra™ Ready-to-use mouse monoclonal antibody cytokeratin (8/18)—product code: RTU-5D3. Available at: http://www.leica-microsystems.com/fileadmin/img_uploads/novocastra_reagents/Novocastra_datasheets/5d3-r-7-ce.pdf. Accessed 03 July 2011