The technique of blue dye mapping was first described for breast cancer by Giuliano et al [
3]. Isosulfan blue dye has been traditionally used the dye used for SLNB for breast cancer. However, its use was associated with a significant number of allergic reactions [
4], some of which are life threatening. Because methylene blue dye has been shown to be equally effective and does not pose a serious risk of severe allergic and hypersensitivity reactions, it was regarded as an acceptable substitute for isosulfan blue dye for SLNB [
5-
8]. Although, the use of the MB dye for SLNB in breast cancer has fewer allergic reactions, its use has been associated with a number of local and systematic complications. Stradling et al, was the first to report adverse skin reactions to methylene blue dye in patients with breast cancer [
9]. In addition, skin eruptions and rashes [
10], subcutaneous tissue necrosis and abscess formation [
11] have been reported in association with the injection of this dye. Furthermore, capsular contraction following breast reconstruction using an implant with intense blue discoloration of the prosthesis was reported in a patient in whom methylene blue dye was used to identify the sentinel lymph node [
12].
In our reported case, severe skin and fat necrosis complicated the peri-tumoral injection of methylene blue dye; This might be due to that methylene blue dye may induce an early foreign body-type reaction characterized by ischemic ulceration, fibrinoid necrosis with eosinophilic infiltration [
13].
Therefore, we recommend the use of Patent Blue V dye instead of MB for SLNB localization in patients with breast cancer in order to avoid such significant complications which may delay subsequent treatment. Patent Blue dye has been reported to cause minor local complications in form of long-term discoloring of the skin at the site of injection [
14]. Although no cases of severe local tissue necrosis has been reported in association with Patent Blue V dye, however, anaphylactic shock has been observed following its injection for SLNB localization [
15,
16]. The risk of allergic reactions can be reduced by using corticosteroids and antihistamines [
4,
17,
18]
In conclusion, the use of MB dye for SLNB identification should be avoided and replace with alternative types of blue dye such as Patent Blue V preferably in conjunction with a radioactive isotope tracer.