09:30 - 12:30, 3 hours, International Conference Hall
Plenary Session 4
Medical Aspects: Surveillance and Treatment of Asbestos-related Diseases
4-A: Asbestos and Non-asbestos Agents in Mesothelioma Pathogenesis and Immunology
Chairs: Yasunosuke Suzuki and Iguchi Hiroshi
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Kouki Inai, Yukio Takeshima, and Kei Kushitani
Department of Pathology, Graduate School of Biomedical Sciences, Hiroshima University, Japan Asbestos Hazards and Mesothelioma Study Group, Japan
ABSTRACT:
In Japan, the epidemiologic study has indicated a progressive increase of mesothelioma during the last decade. In 2003 the research group on diagnosis and treatment of mesothelioma was organized and the comprehensive survey on occurrence and diagnosis of mesothelioma in Japan was performed. On the basis of making inquiries to authorized pathologists by Japanese Society of Pathology, informations about 854 cases of mesothelioma diagnosed pathologically during the period from 1995 to 2002 were gathered from 116 institutions. As the results of analyses on these cases, male / female ratio was 634 (77.3%) / 186 (22.7%). The locations of tumor were divided to 651 cases (77.4%) in pleura, 111 cases (13.2%) in peritoneum, 24 cases (2.9%) in pericardium, 5 cases (0.6%) in tunica vaginalis testis and 50 cases (5.9%) of unknown or indeterminate location. The materials for diagnosis were as follows : 211 cases (25.1%) by autopsy, 231 cases (27.5%) by operation, 202 cases (24.0%) by needle biopsy, 143 cases (17.0%) by VATS biopsy and 106 cases (12.6%) by open biopsy (including double answer). The cases were divided by histological classification as follows : 403 cases (47.9%) of epithelioid type , 153 cases (18.2%) of sarcomatoid type, 180 cases (21.4%) of biphasic type. Immunohistochemical stainings were done at the rates of 76.7% on cytokeratin, 52.5% on EMA, and 42.7% on calretinin and the proportions of positive case were 92.5% in cytokeratin, 74.5% in EMA and 79.7% in calretinin. Tissue blocks of 130 cases among 854 cases could be offered from each of the institutions. The diagnosis of mesothelioma and its histological subtypes were re-confirmed by the research group and immunohistochemical staings were done according to the new informations. On the basis of the results of this investigation, the immunohistochemical methods useful for the accurate diagnosis of mesothelioma will be able to be presented.