川田 慎一¹, 米満 幸一郎¹, 盛本 真司¹, 小村 寛¹, 白石 真紀¹, 立山 由香理¹, 上國料 章展¹, 有村 麻衣子¹, 内園 均²

Shinichi KAWADA¹, Kouichirou YONEMITSU¹, Shinji MORIMOTO¹, Hiroshi KOMURA¹, Maki SHIRAISHI¹, Yukari TATEYAMA¹, Akinobu KAMIKOKURYO¹, Maiko ARIMURA¹, Hitoshi UTIZONO²

¹鹿児島市医師会病院生理機能検査室, ²鹿児島市医師会病院消化器内科

¹Department of Clinical laboratory, Kagoshima medical association Hospital, ²Department of Gastroenterology, Kagoshima medical association Hospital

キーワード : ultrasonography, simple renal cyst, cystic renal cell carcinoma, detection rate

目的：我々は, 当院の1994 年4 月から2004 年3 月まで10 年間の人間ドック腹部超音波検査(US) において腎精密検査 統計をもとに, 超音波検診の現状と有効性について検討を行った. 対象と方法：腎のUS 有所見実人数4,339 人の中で, 当院CT での精密検査を施行した129 人を対象とし, US 所見とCT 診断結果について比較検討した. 結果と考察：対象 の129 人中, US で腎腫瘍を疑った73 人のCT 診断結果は, 正常45 人(61.6％), 単純性腎嚢胞13 人(17.8％), 複雑性 腎嚢胞5 人(6.8％), 悪性腫瘍疑い5 人(6.8％), 腎血管筋脂肪腫2 人(2.7％), 腎盂拡張1 人(1.4％), 肉芽腫1 人 (1.4％), 奇形腫1 人(1.4％) であった. 悪性腫瘍疑いのうち4 例はMRI を施行し, 腎癌が疑われ手術を施行した. そ の結果, 病理組織学的に腎癌と確定診断のついた症例は2 例で, 当院人間ドックUS における腎癌検出率は0.046％であっ た. 腎癌2 例のうち, 1 例はUS で腎嚢胞と嚢胞性腎癌の鑑別ができず手術に至るまで3 年間精査されなかった. 結論： 単純性腎嚢胞と確定できない場合は, US 再検や精密検査を積極的に施行することが必要と考えられた. またUS 施行技 師の技術と判読医のレベルの向上を図るために, 精密検査の情報を関係者にフィードバックするシステム構築の必要性が あると思われた.

Purpose: The current state and effectiveness of abdominal ultrasonography (US) were investigated by reviewing statistical data for US of the kidney as part of complete medical screenings conducted at our institution between April 1994 and March 2004. Methods. Among 4339 individuals with US findings, computed tomography (CT) was performed on 129 individuals at our institution. Among these individuals, US findings and CT diagnoses were compared and analyzed. Results: US findings indicated renal tumors in 73 of the 129 subjects, and the breakdown of CT diagnoses for these 73 individuals was as follows: no lesion, n＝45 (61.6％); simple renal cyst, n＝13 (17.8％); complicated renal cyst, n＝5 (6.8％); suspected malignant tumor, n＝5 (6.8％); renal angiomyolipoma, n＝2 (2.7％); pelvic dilatation, n＝1 (1.4％); granuloma, n＝1 (1.4％); teratoma, n＝1 (1.4％). Magnetic resonance imaging (MRI) was performed on 4 of the 5 subjects with suspected malignant tumor, and surgery was performed in all 4 cases with suspected kidney cancer. Kidney cancer was histopathologically confirmed in 2 patients, resulting in a detection rate of 0.046％ for kidney cancer by US as part of a complete medical screening. In the 2 patients with kidney cancer, differentiating cystic renal cell cancer from a renal cyst was not possible based on US findings alone in 1 patient, and no thorough examinations were performed in the 3 years leading up to surgery. Conclusions: These results suggest that additional US and thorough examinations are necessary if a lesion cannot be confirmed as a simple renal cyst on initial US. Furthermore, to improve the skill levels of healthcare professionals who perform and interpret US, a feedback system should be established where data related to complete medical screenings are available to the personnel involved.