Objective: The pre-lymphatic system was initially described in the 1960s by Casley-Smith and Florey. It consists of CD34 positive fibroblasts lined stromal spaces communicating with the lymphatic capillaries. The aim of the following investigation was to compare the lympho-vascular density and pre-lymphatic network density of breast tissues in the context of the menstrual status of the patients. Method: Formalin-fixed, paraffin embedded tissue specimens from 105 patients with primary breast cancer were studied. Tumor-free tissue materials were selected. Tissue processing and immunohistochemical staining with D2-40 and CD34 antibody was performed in accordance to standard laboratory protocols. Quantitative evaluation of the lymphatic and pre-lymphatic system was performed. The Kruskal -Wallies test was used to compare differences between the median values of the studied variables. Statistical significance of the differences was considered if p<0.05. Results: The pre-lymphatic network was found to be significantly more dense in menstruating, compared to menopausal women K-W=61.04; p<0.0001 n=105. Lymphatic vascular density was higher in menstruating compared to menopausal women K-W=7.60882; p=0.006; n=105. Conclusion: Involution changes in the pre-lymphatic and lymphatic system of the breast were found to appear in postmenopausal women. This may be the explanation for the slow local progression of breast cancer observed often in elder patients.