Lymphatic vessels are largely restricted to the myometrium in mouse uterus. (A) Representative photomicrograph of podoplanin (brown) and CD31 (blue) dual-immunostaining in mouse uterus highlighting the lymphatic and blood vessels, respectively. An area of a transverse section is shown. (B) Higher magnification of tissue within boxed area in A. Note the pale but distinct non-lymphatic podoplanin immunoreactivity in the connective tissue around the myometrial arteriole (white arrow). (C) Lyve-1 immunostaining is also useful for identifying uterine lymphatic vessels, as seen in this photomicrograph from a section serial to that in B. (D) VEGFR-3 immunostaining in a section serial to that in C (Inset: isotype-matched control for VEGFR-3). VEGFR-3 immunoreactivity is not useful as a marker of uterine lymphatics as varying levels of immunostaining are also observed in other uterine cellular components. (E, F) Representative photomicrographs of human VEGF-D (brown)/Lyve-1 (blue) and (G, H) VEGFR-3 immunostaining in NOD SCID mouse uterus inoculated with VEGF-D expressing 293EBNA cells. Note: F and H are higher magnification images of tissue within boxed area in E and G, respectively. Black arrows: lymphatic vessels. Dotted line delineates myometrium and endometrium. en: endometrium, m: myometrium, t: tumor.