The publication of important paper by R. Kloos et al. “Medullary Thyroid Cancer: management guidelines of the American Thyroid Association” [1] has been a great achievement in the world of thyroidology in general and thyroid cancer in particular. The guidelines were evidence based for management of medullary thyroid cancer, a very rare cancer type, known well only to few thyroidologists. These were crucial factors for their endorsement by the European Thyroid Association. However, among some European thyroidologists the document raised a vivid online discussion, which led to the organization of this topic as the program of the European Thyroid Association – Cancer Research Network Meeting (ETA-CRN) in Lisbon in September 2009. The program of this event is presented in Additional file 1. About 140 participants, mostly European thyroidologists, took part in the discussion [2]. This supplement of Thyroid Research is to summarize aroused debate on the subjects in question. The publication followed the request from ETA-CRN General Assembly in Pisa, 2012 and the disputants were invited to present their views. Therefore, Ulla Feldt-Rasmussen, President of ETA-CRN and Barbara Jarzab, Secretary of ETA-CRN undertook the role as Guest Editors of this supplement.

We are very thankful that the authors agreed to join the supplement on a voluntary basis and undertook the challenge to formulate conclusions from Lisbon and update them. We believe that more than a 3-year long delay allowed to balance and objectify the assessment of the ATA medullary thyroid cancer guidelines well. We have also invited colleagues, members of ETA-CRN, who took active part in the online discussion but did not have the possibility to join discussion in Lisbon [3, 4]. Please note, that all invited articles have been peer reviewed before publication, according to BioMed Central Guidelines for externally administered peer-review. We asked all peer reviewers to declare their competing interests in relation to reviewed paper.

We hope this supplement, devoted to medullary thyroid cancer, will enrich our knowledge about this rare disease and its treatment, and will become a positive contribution in the study of its nature.