小牧 宏一¹, 宮坂 千晶³, 山田 勉², 阿部 好伸¹, 斎藤 頴¹, 小沢 友紀雄¹

Koichi KOMAKI¹, Chiaki MIYASAKA³, Tsutomu YAMADA², Yoshinobu ABE¹, Satoshi SAITO¹, Yukio OZAWA¹

¹日本大学医学部第二内科, ²日本大学医学部第二病理学教室, ³オリンパス光学工業

¹The Second Department of Internal Medicine, Nihon University School of Medicine, ²The Second Department of Pathology, Nihon University School of Medicine, ³Olympus Optical Co. Ltd

キーワード : Acoustic microscopy, Primary pericardial malignant mesothelioma, Tissue characterization

Primary pericardial malignant mesothelioma is a rare tumor. The echocardiographic findings of 12 cases shows that there are two different types of tumor: hypoechoic and hyperechoic tumors to data (Table 1). For evaluation of tumor echogram, two cases of malignant pericardial mesothelioma were observed using a scanning acoustic microscope (SAM: OLYMPUS UH3). Case 1 (53-year-old male): epithelial type pericardial mesothelioma. The brightness of the tumor was observed to be hypoechoic, the same finding as brightness of pericardial effusion by echocardiogram. Case 2 (45-year-old male): mixed type pericardial mesothelioma. The brightness of tumor was observed to be hyperechoic, the same as the brightness of cardiac muscle by echocardiogram. SAM with a 200 MHz acoustic lens was used for examination. Using the 3Z mode method, an extensive white zone was observed in tumor of case 1 as compared with the tumor of case 2 and each myocardium. The velocity of the surface acoustic wave (Vsaw) of tissue was measured by FFT analysis of V(z) curves. Vsaw in the tumor of case 1 was lower than that in case 2 and each myocardium. The echocardiographic brightness of pericardial malignant mesothelioma was due to the acoustic homogeneity of the tissue, therefore, white zone of 3Z mode image indicates acoustic homogeneity of a specimen. SAM and echocardiography are thus useful for determining the pathologic type of pericardial mesothelioma.