[In situ mammary duct carcinoma with microinvasion. Which axillary lymph node exploration?]

Specify the role of axillary lymph node removal in micro-invasive in situ duct carcinomas (DCIS-MI) of the breast with a series of 107 consecutive cases.

Single-centre, retrospective, anatomoclinical study with application of the European guidelines adopting as pathological definition the presence of areas of micro-invasion not exceeding 1mm. Axillary lymph node dissection was systematically complete and was preceded by the search for the sentinel node in 10 patients using the isotope method.

Lymph node invasion was revealed in 8 cases in the global population (7.5%). All the cases except one exhibited typical deleterious histological features: comedo architectural sub-type, high nuclear grade, and size of the lesion>3 cm. The lymph node invasion was of 18.5% in the sub-group of high-grade micro-invasive comedo-carcinomas measuring more than 3 cm.

Contrary to those exhibiting pure DCIS, DCIS-MI patients require surgical exploration of the armpit, the most appropriate modalities of which are currently debated: classical axillary lymph node dissection or search for the sentinel lymph node; the selective lymphadenectomy procedure is not yet a consensually validated technique.