The surgeon, the tattoo and the black lymph node

Abstract

We read with interest the recent article by Yang & Creagh on black lymph node related to tattooing and their potential pitfalls. The potential migration of tattoo pigments in the draining lymph nodes (LN) was already suspected by the end of the XIXth century, but the first case of “black lymph nodes” was reported only more than 15 years ago. Recently, the SKH-1 mouse model, used for tattooing studies, was showed to present a rapid pigmentation of the draining LN of the tattooed area after the procedure. Tattoo pigments may be responsible for acute or chronic, transient or permanent palpable LN, that may raise concerns for tumoral or infective process. Since 1996, numerous articles have reported the occurrence of black LN and the potential risk related of mistaking such LN with a metastatic melanoma. First of all, due to the nature of tattooing and the physiopathological reaction that occurs in the dermis, we can safely say that every tattooed individual does have tattoo pigments in variable quantity in their regional LN. Therefore such discovery should not be anymore a surprise for any surgeon. Second, the diagnosis of malignancy is made upon histopathological examination and not upon clinical aspect of the LN, even if the context could suggest the worse. The pathologist can not mistake melanoma malignant cells with tattoo pigments due to the aspect and peculiar location of the pigments in the LN sinuses and thanks to specific stainings. However, the question whether a pathologist may miss metastatic cells