Microvillous Inclusion Disease: An analysis of 4 cases

Kim, Daesu; Beck, Nam Seon; Suh, Yeon Lim

Abstract

Microvillous inclusion disease (MID) or congenital microvillous atrophy is a rare cause of intractable, persistent secretory diarrhea shortly after birth or at birth. The prognosis of MID is very poor and most of the reported patients have died within 6.5 years. Diagnosis is based on the ultrastructural demonstration of intracytoplasmic inclusion of microvilli. There have been several cases reported in the literature. To evaluate the clinicopathologic features of MID, we have reviewed 4 cases of MID which was confirmed by the ultrastructural study of the duodenal biopsy. All patients suffered from life-threatening diarrhea since birth. Many other radiologic or laboratory findings were of no value in the evaluation of causative agents. One of the patients died of the disease and remaining patients have been alive on intravenous fluids or total parenteral nutrition. Histological findings of all cases were similar and characterized by varying degrees of mucosal atrophy and chronic inflammatory cell infiltration in the duodenal mucosa. PAS stain revealed a discontinuous brush border over the atrophic villous surface with or without small vacuoles in the cytoplasm of the surface epithelium. Ultrastructural changes were found mainly in the surface epithelium of the duodenal mucosa and characterized by the presence of membrane bound inclusions lined by intact or degenerating microvilli, as well as degeneration of surface epithelial cells with loss of microvilli, or with sparse, short microvilli.