Contralateral or bilateral lymph drainage revealed by breast lymphoscintigraphy

Abstract

Sentinel lymph node biopsy (SLNB) is a minimallyinvasive staging procedure for patients with breast cancer.Multiple studies have validated the accuracy of thisprocedure which has become the preferred and standard ofpractice for most surgeons treating breast cancer [1–3].Interestingly, a continuous evolution has been characteriz-ing SLN mapping. In 2002, it was accepted as officialcomponent in the staging process for invasive breastcarcinoma, and the American Joint Committee on CancerStaging Manual has modified the TNM classification forbreast cancer accordingly [4]. However, the AmericanSociety of Breast Surgeons had been recommending againstSLN mapping for patients with significant prior axillary orbreast surgery until December 2005 when the “ConsensusStatement on Guidelines for Performing Sentinel LymphNode Dissection in Breast Cancer” has been revised toinclude patients previously treated with surgery [5]. As faras patients with early breast cancer with no clinicalevidence of lymph node (LN) involvement (cT1-T2 cN0),exclusion criteria to perform breast lymphoscintigraphy(LS) have been thinning considerably in the recent past, andthe only current contraindication to perform breast LS is thepresence of lymphatic congestion (i.e. mastitis) [6–8]. Overthe past 10 years, more than 12,000 breast LS have beencarried out at our Institute, and only 11 cases have beencharacterised by contralateral or bilateral lymph drainage.Accordingly, this phenomenon has been described mostlyas case report [9–13] in literature. More recently, authorshave assessed the feasibility and usefulness of LS byreviewing cohorts of patients with recurrent breast cancerpreviously treated with surgery [14–20]. We here addressthe question with regards to what behaviour should be keptin case of display of contralateral or bilateral LNs on a LS.Should all LNs be excised and brought to pathology forexamination? To what extent should this finding affect thestaging and the treatment of the index breast neoplasia?On our experience we have found 11 cases of uncommonlymph drainage revealed by LS imaging as part of preoper-ative workup in patients with suspected or confirmed breastcancer. Sevenof the 11 patients had already beentreated withsurgery for aesthetic or curative purposes and radiotherapy(three patients) or radio-chemotherapy (two patients).Breast LS was performed according to the standardtechnique in use at IEO [21, 22], with subdermaladministration of 12-15 MBq of