Subdermal laterocranial mapping of sentinel lymph nodes in breast cancer as an alternative to the peritumoral mapping.

Purpose: Peritumoral injection of blue dye is standard method of sentinel lymph nodes (SLN) biopsy in breast cancer. Applying the marker to different locations will be of great benefit in cases in which the peritumoral mapping is difficult to implement. The aim of this study was to demonstrate that the subdermal laterocranial (SLC) mapping with a dye has similar diagnostic reliability to the peritumoral mapping and is applicable for clinical use.
Patients and Methods: 254 patients with operable breast cancer (cT<or=(3 cm)N0M0) underwent SLN mapping. SLC mapping was carried out in 150 patients, and classic peritumoral mapping in 95. In the cases with SLC mapping the dye was injected subdermally in the laterocranial part of the breast, 2-3 cm mediocaudally from the macroscopic contour of the gland. In this location the dye was injected into 3 points. The rest of the procedure followed the protocol for mapping with the standard peritumoral method.
Results: SLC mapping was successful in 145 (97%) of the cases. In 54 (37%) patients the SLN were positive and in 91 (63%) negative. In 2 patients false-negative results were taken. Standard peritumoral mapping was successful in 94 (99%) cases. The SLN were positive in 35 (37%) patients and negative in 59 (63%). False-negative result was seen in 1 patient. Both methods of SLN mapping gave almost identical results.
Conclusion: The laterocranial and peritumoral method of SLN mapping are equal with regard to their diagnostic reliability. The results suggest that the laterocranial method can be used in clinical practice.