芳賀 真代¹, 平井 都始子², 中井 登紀子³, 小林 豊樹⁴, 中村 卓⁴, 丸上 亜希¹, 伊藤 高広¹, 武輪 恵¹, 丸上 永晃², 吉川 公彦¹

Masayo HAGA¹, Toshiko HIRAI², Tokiko NAKAI³, Toyoki KOBAYASHI⁴, Takashi NAKAMURA⁴, Aki MARUGAMI¹, Takahiro ITO¹, Megumi TAKEWA¹, Nagaaki MARUGAMI², Kimihiko KICHIKAWA¹

¹奈良県立医科大学放射線科, ²奈良県立医科大学総合画像診断センター, ³奈良県立医科大学病理, ⁴奈良県立医科大学乳腺外科

¹Department of Radiology, Nara Medical University, ²Department of General Diagnostic Imaging Center, Nara Medical University, ³Department of Diagnostic Pathology, Nara Medical University, ⁴Department of Surgery, Nara Medical University

キーワード : contrast-enhanced ultrasonography, breast cancer, Sonazoid<SUP>&reg;</SUP>, intraductal component, intraductal spread

乳管内進展を伴った乳癌症例では，一般的に造影MRIが広がり診断に有用と考えられている．造影MRIは，重篤な腎障害や気管支喘息のある患者は原則禁忌であるが，超音波造影剤ソナゾイド^®は，安全性が高く腎障害や喘息の既往があっても使用できる．今回我々は，ソナゾイド^®造影超音波で広範囲な乳管内進展を描出できた2例を報告する．1例は喘息，もう1例は透析患者で造影CT/MRIは実施できなかったが，ソナゾイド^®造影超音波では副作用を認めなかった．症例1は73歳女性．マンモグラフィ（MG）で腫瘤から連続する淡く不明瞭な石灰化を区域性に認め乳管内進展が示唆されたが，Bモードでは乳管内進展を疑う所見を認めなかった．症例2は67歳女性．MGで腫瘤近傍に多形性不均一な石灰化が区域性に分布し，Bモードで腫瘤から連続する低エコー域を認め，乳管内進展が示唆された．いずれの症例も，ソナゾイド^®造影超音波で乳管内進展は腫瘤から連続する帯状濃染域として描出され，時間輝度曲線（time intensity curve: TIC）では主腫瘤と同様のピークとwashoutを示した．造影超音波での濃染の広がりの結果から，症例1は部分切除術を症例2は乳房全摘術を選択した．病理では広範囲に拡張乳管内に増殖した乳管内癌成分を認め，病変断端は陰性であり治療方針にも寄与した．

Breast cancers with intraductal components are usually evaluated by contrast-enhanced MRI, but contrast agents for MRI are contraindicated for persons with asthma and severe renal dysfunction. Sonazoid^®, an ultrasound contrast agent, has few side effects, and it can be used in patients with asthma and severe renal dysfunction. We report two cases of breast cancer in which contrast-enhanced ultrasonography (CEUS) was useful in diagnosing intraductal spread. These patients were unable to undergo contrast-enhanced CT/MRI due to asthma and severe renal dysfunction, but they could receive CEUS with no side effects. Case 1 was a 73-year-old woman. On mammography (MG), the tumor and segmental pleomorphic calcifications contiguous to the tumor were recognized, suggesting the presence of intraductal components. However, only the tumor could be detected on B-mode ultrasound. Case 2 was a 67-year-old woman. Segmental pleomorphic calcifications around the tumor were detected on MG, and low echoic regions leading to the tumor were recognized on B-mode ultrasound, indicating the presence of intraductal components. In both cases, CEUS showed streamed zonal enhancement leading to the tumor. On TIC, the intraductal components showed curves equal with their tumors. Based on the results of CEUS, breast-conserving surgery was selected in case 1 and breast removal was selected in case 2. Pathologically, the zonal enhancement regions leading to the tumor reflected intraductal components. CEUS could contribute to surgical planning.