Study on the ratio of lymphocytes to epithelial cells in thymoma

In order to quantify the lymphocyte to epithelial cell ratio (L/E ratio of the thymoma, actual counting was performed. The L/E ratio was investigated in 25 specimens of 22 cases (22 initial tumors and 3 recurrent tumors). L/E ratios ranged from 0.27 to 4.10, and the mean value was 1.93 +/- 0.21. The mean L/E ratio of histologically malignant group was lower than that of the benign group. In the three recurrent cases, L/E ratios of the recurrent tumor decreased in all cases. It was concluded that the epithelial element increases with the adva