ANATOMY OF THE URETHRAL SUPPORTING LIGAMENTS DEFINED BY DISSECTION, HISTOLOGY, AND MAGNETIC RESONANCE IMAGING (MRI) OF FEMALE CADAVERS AND OF HEALTHY NULLIPAROUS WOMEN

Abstract

sizes of individual lymphatic vessels were categorized as small ( 0.5mm). To compare the lymphatic density (counts/mm2), the number of lymphatic vessels of the five random areas was counted in each specimen by light microscopy at low power (x40). RESULTS: LYVE-1 expression and the lymphatic density of muscular propria were significantly higher than those of other layers, including epithelium, lamina propria, perivesical fat, and serosa (p < 0.0001, respectively). The size of lymphatic vessels in muscular propria was significantly smaller than in other layers (p < 0.0001). The greatest distribution of lymphatic vessels was identified in the border areas consisting of lamina propria and muscular propria, or muscular propria and adventitia, including perivesical fat and serosa. CONCLUSIONS: We found that high density of lymphatic vessels was identified in a border area consisting of lamina propria and muscularis propria. When biologically aggressive bladder cancer deeply or widely extends into the muscularis propria, cancer cells potentially invade the lymphatic vessels depending on its volume in this border area. A distribution of lymphatic vessels in normal bladder urothelium in this study possibly supports the clinical association of lymph node involvement with the depth of muscle invasion. LYVE-1 antibody was a useful specific marker for illustration of the lymphatic vessel in conventional paraffin-embedded specimens of the urinary bladder.