Correlation of histologic regression in primary melanoma with sentinel node status.

Importance The influence of regression on the status of the sentinel node (SN) is controversial. In many centers, the presence of regression in thin melanomas supports the performance of an SN biopsy. Objective To identify whether regression in primary melanoma has any influence on SN involvement. Design, Setting, and Participants Retrospective study of melanomas with a Breslow thickness greater than 0.75 mm and undergoing SN biopsy from January 1, 2003, through December 31, 2010, at Instituto Valenciano de Oncologia, which receives melanoma patients from regional hospitals and dermatology practices. Only cases with paraffin blocks or histologic slides representative of the primary tumor an…