1. A study of distribution of mast cells in uterine leiomyomas and myometrium and their relationship to morphology of leiomyomas and patients’ clinical features

Abstract

Introduction Mast cells (MCs) effects on uterine leiomyomas (LMs) are still unclear. Haematoxylin and eosin (H&E) stain is suboptimal for MC visualization. Objectives We compared (1) MC density in LMs with adjacent myometrium (control), morphology of LMs and clinical features and (2) compared MC counts in H&E with Toluidine blue (Tolb), Giemsa, Mast cell tryptase (MCT) and CD117/ckit. Methods We selected 37 LMs from 27 patients and analysed clinical features. Each section of 37 LMs and controls was stained with H&E, Tolb, Giemsa, MCT and CD117. Two observers independently counted MCs in 50 high power fields (hpfs) and averaged to MCs/ 10hpfs and mean value was calculated. MC counts for 37 LMs and 26 controls were analysed and compared with each stain. Number of MCs/10hpf stained with CD117 was compared with size of LMs, degenerative change of LMs, status of endometrium and with the control. Results The mean age of 27 patients was 52.8 years (ranged 31–69). 11 patients presented with fibroids. 25 of 37 LMs were small (≤40 mm). CD117 showed higher number of MCs/10hpfs. H&E count was generally low. 50% of controls have higher counts (≥50/10hpfs). 72% of LMs with hyalinisation and 72.7% with atrophic endometrium showed low MC counts ( Conclusion 1. Tolb and Giemsa were better than H&E for MC count. MCT showed staining problems. CD117 was the best stain. 2. No linear relationship found between LMs size and MC counts. 3. MC count was low in LMs with hyaline degeneration and atrophic endometrium. Further studies are required to find whether MCs are inhibitors or promoters of LMs.