INDICATION OF BREAST CONSERVATIVE SURGERY FOR PRIMARY BREAST CANCER USING COMPUTER GRAPHIC THREE-DIMENSIONAL RECONSTRUCTION OF THE MAMMARY DUCT-LOBULAR SYSTEMS.

乳腺癌的导管内扩散可以沿着乳腺导管/小叶系统（MDLS）发生，而不侵犯组织。由于MDLS中的导管阻塞被认为是乳腺癌广泛导管内扩散的可能风险因素，因此MDLS的结构对接受保乳手术治疗的患者具有重要的治疗意义。一个69岁的女性乳腺导管原位癌（DCIS）的皮下切除术的整个乳房进行了检查，在亚宏观切片的立体显微镜和组织学技术。对所有MDLS的连续2 mm切片进行计算机辅助完整三维重建。所用的整个乳房包含16个MDLS，以乳头为中心放射状排列。16例MDLS中4例（25.0%）有导管狭窄，其余12例无导管狭窄，均为完全独立的区域解剖。在4例MDLS的11个部位观察到导管闭塞。11例连接不同MDLS的导管阻塞中，有2例（18.2%）位于距乳头4cm以上。其余9个连接导管在同一MDLS内;它们的位置从乳头附近到外周区域不等。在所检查的病例中，DCIS仅在单个MDLS内扩展，并且不通过导管内病变在不同MDLS之间扩散。据作者所知，首次对整个乳房中所有MDLS的完整结构进行了三维研究。当导管内病变向周围扩展而不是向中心扩展时，手术期间导管内扩散的风险可能更大。根据MDLS的解剖结构个体化手术切除范围有助于最大限度地减少手术切缘残留癌的风险。

Intraductal spread of breast cancer can occur along the mammary duct/lobular systems (MDLS) with no invasion of tissues. As ductal anastomoses in the MDLS are considered a possible risk factor for extensive intraductal spread of breast cancer, the architecture of MDLS has important therapeutic implications for patients treated by breast-conserving surgery. An entire breast resected by subcutaneous mastectomy from a 69-year-old woman with ductal carcinoma in situ (DCIS) was examined in subgross sections by stereomicroscopic and histologic techniques. Serial 2-mm sections were subjected to computer-assisted complete three-dimensional reconstruction of all MDLS. The entire breast used contained 16 MDLS, radially arranged with the nipple at the center. Of 16 MDLS, 4(25.0%) had ductal anastomoses while the remaining 12 MDLS had no ductal anastomoses and completely independent regional anatomy. Ductal anastomoses were observed at 11 sites in the 4 MDLS. The 2 (18.2%) of 11 ductal anastomoses that connected different MDLS were situated more than 4 cm from the nipple. The remaining 9 connected ducts within the same MDLS ; their location varied from near the nipple to the peripheral region. In the case examined, DCIS extended only within a single MDLS, and did not spread between different MDLS via ductal anastomoses. The complete architecture of all MDLS in an entire breast was studied three-dimensionally for the first time to the authors' knowledge. The risk of extending intraductal spread during surgery may be greater where intraductal lesions extend more peripherally than centrally. Individualizing the extent of surgical resection based on the anatomy of MDLS should help to minimize the risk of leaving residual carcinoma at surgical margins.