Ultrastructural abnormalities essential for diagnosis of Tufting Enteropathy

Abstract

Objective: Tufting enteropathy (intestinal epithelial dysplasia) is a rare congenital enteropathy related to severe intractable diarrhea with early onset due to specific abnormalities of the intestinal epithelium. We report a case with distinguished ultrastructural characteristics. Method: Four-month old male infant was admitted in Pediatric Clinic because of protracted watery diarrhea in a period of 3 weeks and failure to thrive. After thorough clinical and laboratory examination, duodenoscopy was done. Biopsy specimens were fixated in glutaraldehyde and embedded in Durcupan resin. Semi-thin sections dyed with Toluidine Blue and ultra-thin sections treated with Uranyl Acetate and Lead Citrate were made. Results: Light-microscopic analysis shows small intestinal mucosa with variable abnormalities of villous projections, which were flattened in parts. Focally, there was evident crowding of surface enterocytes, disorganization and focal forming of tear-shaped tufts. There was low mononuclear cell infiltration in lamina propria. Electron-microscopic analysis shows reduced number of microvilli of surface enterocytes, with structural disorganization, represented by desmosomes increased in number and length. There was evident tufts formation with disruption of brush border in their vicinity, whereas basement membrane was stratified and laminated. Conclusion: Tufting enteropathy is a rare genetic disease for which transmission electron microscopy is a superior diagnostic tool.