ABSTRACT
One hundred and forty cases of endometrial lesions including 128 endometrial polyps, 7 cases of atypical hyperplasia and 5 cases of endometrial carcinoma were studied for mast cells and macrophages. Thirty six uteri with normal cyclic variations served as a control group. A cyclical variation in the mean mast cell value was observed in the control group with an increase in the secretory phase. Endometrial polyps showed a decrease in average mast cell count compared to the proliferative phase controls. Mast cells were significantly decreased in atypical hyperplasia and were absent in endometrial carcinoma. The observations indicate a hormonal basis for the significant variation in mast cell. Their presence probably suggests benign nature of the lesion. PAS positive macrophages were seen only in 4 endometrial polyps, too small for assessment of their significance.