Breast lymphatic mapping using blue dye and radiocolloid.

I read Dr Kern’s article on the technique of subareolar blue dye injection with great interest. I was also interested in Dr Kern’s reply to the letter by Dr Ahmad Shatila. I was particularly intrigued by the comment made by Dr Kern that the sentinel lymphatic channels provide access to the same sentinel lymph nodes that receive lymph flow from peritumoral injections, and most importantly, that “we know this because of our 0% falsenegative rate achieved in our first study. . . .” I found Dr Kern’s first study compelling but hardly proof-positive that subareolar injections are 100% accurate as claimed. This study included only 40 patients, with 39 having successful mapping. Most importantly, only 15 patients harbored positive nodes. Because all patients with negative nodes will theoretically have a successful mapping, it is only these 15 patients from whom we can draw conclusions concerning the accuracy of the technique. As Dr Kern has demonstrated, the technique of subareolar injection is relatively easy and, most importantly, solves a number of troublesome logistical problems. Accurate injections in patients with deep-lying tiny clusters of microcalcifications and in those with multicentric disease are clearly problematic. Hopefully, further studies will confirm the utility and accuracy of this technique. Although the technique may in fact be highly accurate, I do not believe that we should rush to make sweeping statements based on the study of such small numbers.