河内 伸江¹, 角田 博子¹, 小野田 結¹, 菊池 真理¹, 刈田 映子¹, 松岡 由紀¹, 本田 聡¹, 矢形 寛², 鈴木 高祐³, 齋田 幸久¹

Nobue KAWAUCHI¹, Hiroko TSUNODA¹, Yui ONODA¹, Mari KIKUCHI¹, Eiko KARITA¹, Yuki MATSUOKA¹, Satoshi HONDA¹, Hiroshi YAGATA², Koyu SUZUKI³, Yukihisa SAIDA¹

¹聖路加国際病院放射線科, ²聖路加国際病院乳腺外科, ³聖路加国際病院病理診断科

¹Department of Radiology, St. Lukes International Hospital, ²Department of Breast Surgical Oncology, St. Lukes International Hospital, ³Department of Pathology, St. Lukes International Hospital

キーワード : breast ultrasound, ductal carcinoma in situ, elastography, color Doppler imaging

目的：非浸潤性乳管癌（DCIS）のエラストグラフィ所見について知ることを目的とした．対象と方法：対象は2007年4月からの1年間におけるDCIS 46例である．エラストグラフィではItoらにより低エコー域の歪みを5段階にスコア分類することが提唱されており，これを使用して対象のスコア分類を検討した．腫瘤像形成性病変と腫瘤像非形成病変，病理学的コメド型と非コメド型でスコア分類に違いがあるかどうかを検討した．MMG上の石灰化はマンモグラフィガイドラインで悪性の可能性があるとされるカテゴリー3以上について，その有無を比較検討した．さらに，カラードプラ所見は，視覚的に血流の多寡を4段階に分類して比較検討した．結果と考察：エラストグラフィではスコア1が5例，2が8例，3は18例，4は12例，5は3例であった．良悪性のカットオフを行えるとされるスコア3‐4間で分けると感度32.6％と低かった．腫瘤像形成性病変は22例，腫瘤像非形成性病変は24例で，腫瘤像非形成性病変の方が統計学的に有意にスコアは低かった．病理学的コメド型と非コメド型の分類，MMG上の石灰化の有無，カラードプラ所見とスコアに統計学的有意差はなかった．結論：DCISではスコアが低いものが多く，特に腫瘤像非形成性病変でその傾向が強く留意する必要がある．

Purpose: The purpose of this study was to examine ultrasound elastographic images of ductal carcinoma in situ (DCIS). Subjects and Methods: Forty-six cases of DCIS were encountered from April 2007 to March 2008. The elasticity of the hypoechoic area was divided into five grades by ultrasound elastography. We reviewed the elasticity scores of subjects obtained by elastography (score of 1 to 5). The elasticity scores were compared with B-mode imaging (mass image-forming lesions and non-mass image-forming lesions), color Doppler imaging, pathological finding (comedo and non-comedo type), and calcifications (category 3, 4, or 5 according to the mammography guideline) on MMG. Vascularity on color Doppler imaging was visually classified into four grades: avascular, hypovascular, vascular, and hypervascular. Results and Discussion: The elasticity scores were as follows. There were five lesions with a score of 1, eight lesions with a score of 2, 18 lesions with a score of 3, 12 lesions with a score of 4, and three lesions with a score of 5. When a cutoff point between score 3 and 4 was used, the sensitivity was lower (32.6%) when compared with the sensitivity in the literature. Twenty-two lesions were mass image-forming and 24 lesions were non-mass image-forming. The scores of non-mass image-forming lesions were statistically lower than those of mass image-forming lesions. There was no significant relationship between comedo/non-comedo type and the elasticity score. There was also no relation with calcifications on MMG. Vascularity did not affect the score in any of the cases. Conclusion: There are more cases with lower elasticity scores in DCIS, especially in cases with non-mass image-forming lesions.