Label‐free laser scanning microscopy targeting sentinel lymph node diagnostics: A feasibility study ex vivo

Abstract This proof‐of‐concept, observational study investigates the potential for label‐free, laser scanning microscopy to identify melanoma metastatic features in lymph node tissues ex vivo ‐ exploring the translational potential targeting sentinel lymph node diagnostics. Ten lymph node samples, of which seven are positive for melanoma metastases and three negative, were obtained from a tissue biobank. Imaging data acquired using multiphoton microscopy ex vivo were compared with histopathological findings. Morphologic features characteristic for histopathologic diagnosis of melanoma metastasis were confirmed in the positive samples. Four of the samples were complementary studied with reflectance mode confocal microscopy; however, visualization was found restricted to fibrous structures in this case. To conclude, the results imply that multiphoton microscopy based on autofluorescence is a promising label‐free technique for visualization of cellular features in lymph node tissues.