Increase in lymphatic vessel endothelial hyaluronan receptor 1 positive sinus areas in tumor-bearing sentinel lymph nodes. (A)-(D) Double immunofluorescent images of tyrosinase-related protein 1 (TRP-1; green) and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1; red) in tumor-bearing lymph nodes (LNs). Tumor-bearing sentinel LNs in Grade 1 (A), Grade 2 (B), and Grade 3 (C) showed increases in LYVE-1-positive sinus area in the medulla. High-magnification images of the medullary portion of Grade 3 LN (D). Arrowheads, TRP-1-positive melanoma cells. (E) Measurement of LYVE-1-positive lymphatic sinus area in control LNs and tumor-bearing LNs of each grade. Columns, mean; bar, standard error. *, P<0.05 relative to controls. **, P<0.001 relative to controls.