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

乳腺癌可沿乳腺导管/小叶系统(MDL)发生导管内扩散，不侵犯组织。由于MDLS中的导管吻合被认为是乳腺癌广泛扩散的一个可能的危险因素，MDLS的结构对接受保乳手术的患者具有重要的治疗意义。对1例69岁女性导管原位癌(DCIS)患者行皮下乳房切除术，采用体视显微镜和组织学技术对整个乳房进行亚大体切片检查。对所有MDL进行计算机辅助下完整的2 mm断层三维重建。所用的整个乳房包含16个MDL，放射状排列，乳头位于中心。16例MDL中，4例(25.0%)有导管吻合，其余12例无导管吻合，区域解剖完全独立。在4个MDL中，有11个部位观察到导管吻合。在11个连接不同MDL的导管吻合口中，有2个(18.2%)位于距乳头4 cm以上。其余9条导管连接在同一个MDL内；它们的位置从乳头附近到周围区域不同。在检查的病例中，DCIS仅在单个MDL内延伸，而不会通过导管吻合术在不同MDL之间扩散。据作者所知，作者首次对整个乳房中所有MDL的完整结构进行了三维研究。当导管内病变更多地向外扩散而不是向中央扩散时，手术中扩大导管内扩散的风险可能更大。根据MDLS的解剖，个体化的手术切除范围应有助于将残留癌留在手术切缘的风险降至最低。

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.