Microvillus inclusion disease: A clinicopathological study from western region of Saudi Arabia

Microvillus inclusion disease (MVID) is a rare autosomal recessive disorder due to defective apical surface of the enterocytes presenting with protracted diarrhea from birth. The aim of the study is to describe the pattern of MVID in pediatric population of King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. This retrospective cohort study used small intestinal biopsies submitted to the histopathology laboratory of KAUH between January 2002 and December 2011 from infants aged 0–24 months with intractable diarrhea. Histological slides and pathology reports were reviewed. PAS and CD10 were performed if not available along with electron microscopic examination of the cases and review of the patients’ medical charts. Four (10.5%) cases of MVID were found among 38 small intestinal biopsies submitted to the laboratory with the above mentioned criteria. Two (50%) were females. The four presented with intractable diarrhea during their first week of life that required support with parenteral nutrition. All have died of their disease in their infancy. Light microscopy of their small bowel biopsies showed moderate to severe villous atrophy in all of the four cases. PAS and CD10 immunostain showed loss of the sharp staining of the brush border. Ultrastructural examination of the intestinal epithelial lining demonstrated atrophic surface microvilli in the apical portion of the enterocyte cytoplasm characteristic microvillus inclusions. In conclusion, MVID is a rare fatal disorder with no sex predilection. Clinicians and pathologists should consider it in the differential diagnosis of infants presenting with chronic intractable diarrhea.