Ultrastructural evidence for bladder MAST cell degranulation and their imminent association with nerve fibers in patients with interstitial cystitis

Abstract

The ultrastructure of human mast cells (HMCs) in various diseases has been well documented; however, detailed morphological description of human bladder mast cells (HBMCs) in patients with interstitial cystitis (IC) is incomplete. The present study was undertaken to reveal any morphological modifications of human bladder mast cells (HBMCs) from the IC patients and to investigate the spatial relationships between nerve fibers and these mast cells at the ultrastructural level.Fresh-fixed surgical biopsy specimens from IC patients as well as paraffin blocks of IC retrieved through our medical record archival system were processed with routine and deparaffinization methods for transmission electron microscopy (1). No differences in mast cell morphology were noticed between the fresh-fixed or paraffin embedded tissues.The general electron microscopic appearances of the HBMCs in IC located in both mucosa and muscle layers were similar to those of HMCs observed in other sites where mastocytosis may occur due to various pathological processes (Fig. 1).