Cytoplasmic vacuolization of enterocytes: an unusual histopathologic finding in juvenile nutritional megaloblastic...

We report a case of juvenile nutritional megaloblastic anemia with emphasis on the histologic findings in the upper gastrointestinal system, including the previously unreported feature of periodic acid-Schiff (PAS)-negative, Alcian blue-negative cytoplasmic vacuoles (CV) in duodenal enterocytes. These CV were reminiscent of those described in abetalipoproteinemia; however, the patient's lipid profile was normal. All histopathologic changes in the upper gastrointestinal tract (with the exception of mild reflux esophagitis) reverted to normal following parenteral administration of vitamin B12. This case supports the notion that CV in enterocytes are a component (albeit a rare one) of the histopathology in cobalamin deficiency.