The prognostic significance of tumor lymphangiogenesis and lymphatic vessel density in endometrioid carcinoma of the uterine corpus

The present study aimed to assess the prognostic significance of tumor lymphangiogenesis and lymphatic vessel density (LVD) in endometrioid carcinoma of the uterine corpus. The association between LVD and various factors, including lymphatic vessel invasion (LVI), and nodal metastases, were investigated. Among 202 surgically treated cases, 19 cases with nodal metastases with the infiltration reaching the outer-half myometrium (N+ group) were selected. The LVDs of hotspots in each case were examined at 100× magnification on D2-40 stained slides of the inner- and outer-half myometrium of the peritumoral, and control compartments. Furthermore, for the peritumoral compartment, the LVDs in two types of areas, LVI-present and LVI-absent, were examined for each location of myometrium, which amounted to 6 spots/case. They were statistically compared. Second, to determine whether the existing myometrium influenced LVD, LVDs in the intratumoral compartment were investigated, which were defined as a region where residual muscular tissue was unrecognizable with desmin-immnostaining. As a negative control group, LVDs of the inner- and outer-half myometrium of the peritumoral, and control compartments of 29 cases without nodal metastases in stage IB (N- group) were examined. No significant association was identified between the LVD and frequency of LVI. However, the LVDs in the peritumoral compartment and inner-half myometrium were higher compared those in the control compartment, and outer-half myometrium in N+ and N- groups, respectively. No significant differences were identified in LVD of the peritumoral compartment between groups. The lymphatic vessels were absent where the existing muscular tissue was absent in 16/19 cases. Although higher LVDs in the peritumoral compartment suggested tumor lymphangiogenesis, it was not associated with LVI and nodal metastases. Other factors that influenced LVD were the location in the myometrium and the existing myometrium.