濵田 充生¹, 小西 豊², 岩崎 信宏³, 杤尾 人司³, 中村 仁美³, 太田 圭子³, 曾我 登志子³, 森本 義人³, 橋本 隆², 梶原 建熈²

Michio HAMADA¹, Yutaka KONISHI², Nobuhiro IWASAKI³, Hitoshi TOCHIO³, Hitomi NAKAMURA³, Keiko OTA³, Toshiko SOGA³, Yoshito MORIMOTO³, Takashi HASHIMOTO², Tatehiro KAJIWARA²

¹西神戸医療センター臨床検査技術部, ²神戸市立中央市民病院第一外科, ³神戸市立中央市民病院腹部超音波室

¹Clinical Laboratory, Nishikobe Medical Center, 5-7-1 Koujidai, Nishi-ku, Kobe 651-2273, Japan, ²First Department of Surgery, Kobe City General Hospital, 4-6 Minatojimanaka-machi, Chuo-ku, Kobe 650, Japan, ³Section of Abdominal Ultrasound, Kobe City General Hospital, 4-6 Minatojimanaka-machi, Chuo-ku, Kobe 650, Japan

キーワード : Breast cancer, Lobular carcinoma in situ, Ultrasonography

Lobular carcinoma in situ (LCIS) of the breast is a rare disease, especially in Japan. That is usually found incidentally in specimens excised during examination of other lesions. It is often multicentric, and it tends to involve the bilateral mammary glands, either synchronously or metachronously. Subsequent invasive cancers can develop more than twenty years after the diagnosis of LCIS. Unlike other types of breast cancer, LCIS consists of small round cells with uniform nuclei and shows scarce stromal reaction; it is therefore more difficult to palpate, prove with aspiration biopsy, and visualize on mammography. Although some workers have described it as a benign lesion and others have regarded it as an intermediate stage in the development of invasive lobular carcinoma, LCIS is generally recognized as a special type of breast cancer. The sonographic appearance of LCIS has rarely been described. Here we present two cases of LCIS detected on sonography performed in follow-up study after surgery for breast cancer or on screening of the side opposite the side with breast cancer. In both cases, the lesion was about 5 mm in diameter and was not palpated preoperatively. We were able to use sonography to detect these small lesions and to diagnose them as malignant. Sonography showed the irregular margin of the lesion in both cases studied here and it detected attenuation in the deeper part of one. We expect that sonography will prove useful in the detection and diagnosis of small LCIS, and it may prevent some cases of overtreatment by radical mastectomy and other methods.