Assessment of accuracy of axillary sentinel lymph node biopsy in medially located breast cancer using methylene blue injection technique: our institute experience

Background Axillary lymph node status is the single most important prognostic factor in breast cancer. Sentinel lymph node biopsy (SLNB) can give an idea about the axillary nodal status, with a high rate of identification. Because the upper outer quadrant is the most common site for breast cancer, most studies of SLNB of the breast have been performed in patients with breast cancer mostly located in this quadrant of the breast, whereas the medial quadrants have much been less studied. In this study, we evaluate the axillary SLNB in medially located breast cancer only, using methylene blue injection technique, regarding identification rate, accuracy rate, and false negativity rate (FNR). Patients and methods The study included 42 female patients with medially located breast cancer and negative axilla, scheduled for modified radical mastectomy or conservative breast surgery. Overall, 4 milliliters of methylene blue 1% was injected in the peritumoral tissue. Sentinel lymph node(s) (SLN) and other axillary nodes were individually sent for pathological assessment. Results Average time taken from methylene blue injection until SLN(s) identification and dissection reached 45 min. SLN identification rate was 92.9% of the patients. The number of SLN removed per patient ranged from 1 to 3 nodes. The number of axillary lymph node removed during axillary lymph node dissection ranged from 10 to 22 nodes. Accuracy rate was 88.1%, and SLN FNR was 4.8%. Conclusion Axillary SLNB is highly valid in medially located breast cancer, with high identification and accuracy rates and low FNR.