A clinicopathological study on diagnostic techniques for malignant mesothelioma in dogs and cats

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17580278
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Clinical veterinary science
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: MACHIDA Noboru Tokyo University of Agriculture and Technology, Institute of Symbiotic Science and Technology, Professor, 大学院共生科学技術研究院, 教授 (20219364)
• Co-Investigator(Kenkyū-buntansha): TANAKA Ryo Tokyo University of Agriculture and Technology, Institute of Symbiotic Science and Technology, Associate Professor, 大学院共生科学技術研究院, 助教授 (70334480)
• Project Period (FY): 2005 – 2006
• Keywords: Canine / mesothelioma / immunohistochemistry / synovial sarcoma / lung adenocarcinoma / mammary adenocarcinoma / vimentin / cytokeratin

Research Abstract

Mesothelioma is a malignant epithelial tumor originating from the serosal surface of body cavities and its incidence has increased in recent years. Because serosal surfaces are a common site of metastatic spread for a variety of malignant tumors from internal organs, including lung and mammary adenocarcinomas, the separation of malignant mesothelioma from such adenocarcinomas can be a major challenge. Immunohistochemistry has proven valuable for the diagnosis of malignant mesothlioma, although no specific antibodies have yet been developed that can be accepted as exclusive for these tumors. The purpose of this study was to evaluate the value of immunochemistry in the accurate diagnosis of mesothelioma.
Surgical and necropsy specimens from 7 cases of mesothelioma, 6 cases of synovial sarcoma (SS), 5 cases of lung adenocarcinoma (LA), and 14 cases of mammary adenocarcinoma (MA) were evakuated immunohistochemically. A broad spectrum monoclonal antibodies was applied: vimentin, calretinin, thrombomodulin, cytokeratin 5/6, EMA, CEA, Ber-EP4, and MOC-31. These antibodies included markers that are commonly expected to react with mesothelioma ("positive" markers and markers that are not commonly expected to react with mesothelioma ("negative" markers).
Vimentin was positive in 100% of mesothelioma, 100% of SS, 0% of LA, and 57.1% of MA.; Calretinin only in 7.1% of MA ; cytokeratin 5/6 in 100% of mesothlioma, 33.3% of SS, 100% of LA, and 100% of MA; and EMA in 14.3% of mesothelioma, 83.3% of SS, 100% of LA, and 85.7% of MA. Thrombomodulin, CEA, Ber-EP4, and Moc-31 were negative in all tumors examined in the present study. Our results demonstrate that the significant usefulness of a combination of vimentin and cytokeratin 5/6 as positive markers, and of EMA as a negative marker. The 3-antibody immunohistochemical panel showed the sensitivity of 85.7% and the specificity of 100%.