Aim: Several different injection techniques are currently used for sentinel node (SN) identification in patients with breast cancer. Some studies suggest that the subareolar plexus drains lymph from the whole breast to the same axillary SN. In order to test this hypothesis, we ascertained whether subareolar blue dye injection and subdermal radioisotope injection close to the tumour identify the same axillary nodes.
Methods: One day prior to surgery, 50 patients with breast cancer underwent subdermal injection of 30-40MBq of 99m-Tc colloidal albumin (Nanocoll) at the site of the cutaneous projection of the tumour. Ten minutes before surgery, each patient received a subareolar injection of 2-3cc of patent blue. All axillary radioactive nodes and blue-stained nodes were excised and a histologic examination was made.
Results: Radioisotope marked the SNs in 47/50 (94%) cases, and the blue dye in 43/50 cases (86%). In three cases, SNs were not identified with either method. Of the 43 cases in which both the tracers reached the axilla, in 40 (93%) the SN was hot and blue-stained, while in 3 cases the two tracers identified different nodes.
Conclusions: Our findings suggest that subareolar injection and subdermal injection elsewhere in the breast usually identify the same SN. Subareolar injection appears to be particularly valuable in patients with multicentric or deep non-palpable breast tumours.