This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Waalkes, M. P. Articles by Issaq, H. J. Search for Related Content PubMed PubMed Citation Articles by Waalkes, M. P. Articles by Issaq, H. J.

Inflammatory, Proliferative, and Neoplastic Lesions at the Site of Metallic Identification Ear Tags in Wistar [Crl:(WI)BR] Rats

Laboratory of Comparative Carcinogenesis, Division of Cancer Etiology, National Cancer Institute [M. P. W., S. R., K. S. K.], and Chemical Synthesis and Analysis Laboratory, Program Resources Incorporated [H. J. I.], Frederick Cancer Research Facility, Frederick, Maryland 21701

During a 2-yr study of carcinogenesis by CdCl₂ in male Wistar [Crl:(WI)BR] rats, weekly clinical observations during the last 6 mo of the study revealed many cases of persistent tumor-like masses at the site of the metal identification tags in the ears of the animals. A total of 14 tumors (mostly compound osteosarcomas) was diagnosed in 168 rats. Histologically, almost 90% of the rats in this study (henceforth referred to as Study I) showed some significant lesion at the tag site including various degrees of chronic inflammation, chondrous hyperplasia, and osseous metaplasia of the pinnal cartilage. In marked contrast, only two tumors were detected in 193 animals in a second study (Study II) in the same strain of rats, and only 56% of the rats had lesions at the tag site. A high incidence (>25%) of clinically severe inflammation at the tag site was seen early in Study I and persisted during the first 6 mo of the study, while the incidence of such reactions in Study II was never more than 1%. Elemental analysis of the tags provided no explanation for the differences between the two studies, as tags used in both studies were of the same composition, predominantly nickel and copper. Metallic internal prostheses have induced local malignancies in humans and animals, and the present observations provide further evidence of the hazard posed by such devices at the site of prolonged contact with tissues. These findings suggest that a persistent tissue reaction may be an important factor in tumor development.

¹ To whom requests for reprints should be addressed, at Laboratory of Comparative Carcinogenesis, National Cancer Institute, Frederick Cancer Research Facility, Building 538, Room 205E, Frederick, MD 21701.

Received 9/23/86. Revised 1/22/87. Accepted 1/29/87.

This article has been cited by other articles:

				M. Kitagaki and M. Hirota Auricular Chondritis Caused by Metal Ear Tagging in C57BL/6 Mice Veterinary Pathology, July 1, 2007; 44(4): 458 - 466. [Abstract] [Full Text] [PDF]

				X. Li, J. Eckard, R. Shah, C. Malluck, and K. Frenkel Interleukin-1{alpha} Up-Regulation in Vivo by a Potent Carcinogen 7,12-Dimethylbenz(a)anthracene (DMBA) and Control of DMBA-induced Inflammatory Responses Cancer Res., January 1, 2002; 62(2): 417 - 423. [Abstract] [Full Text] [PDF]

				J. D. Thurman, D. L. Greenman, R. L. Kodell, and A. Turturro Oral Squamous Cell Carcinoma in Ad Libitum-Fed and Food-Restricted Brown-Norway Rats Toxicol Pathol, March 1, 1997; 25(2): 217 - 224. [Abstract] [PDF]

				G. N. Rao and J. Edmondson Tissue Reaction to an Implantable Identification Device in Mice Toxicol Pathol, April 1, 1990; 18(3): 412 - 416. [Abstract] [PDF]