An Enigmatic Case of Chronic Diarrhea, Deciphered

Abstract

Purpose: A 67-year-old female presents with two years of persistent watery, nonbloody diarrhea. Medical history is significant only for distal esophageal narrowing status post myotomy. Previous workup had included serologic testing for celiac disease, infectious workup, and neuroendocrine markers all which had been normal. Upper endoscopy demonstrated diffuse inflammation of the esophagus with biopsies revealing complete villous atrophy, thickened subepithelial collagen bands with intraepithelial lymphocytosis consistent with collagenous sprue. She was initiated on oral budesonide as well as gluten free and limited lactose diet with significant improvement on discharge. Collagenous sprue is an extremely rare disorder, characterized by diarrhea and severe malabsorption accompanied by histological findings of subepithelial collagen deposition and severe villous atrophy of the small bowel mucosa. Its exact etiology remains under investigation with proposed links to both celiac disease and refractory sprue. Regardless of the etiology, collagenous sprue is thought to represent a poor prognosis with severe morbidity and mortality. Endoscopy may be nonspecific as collagenous sprue, celiac disease, and dyspepsia may show reduction of mucosal folds, scalloping with diffuse granularity. On histopathologic examination, there is presence of a subepithelial collagen band that extends into the lamina propria, however there is no current consensus as to what represents a significant increase in subepithelial collagen with many proposers suggesting thicker than 10-12 μm. Moreover, the degree of mucosal abnormality seen in biopsy does not correlate with severity of clinical symptoms, but rather the overall length of the involved segment appears to be much indicative. The pathophysiology is not completely understood, with thoughts of increased expression of fibrogenic genes, especially procollagen I and increased eosinophils contributing to progression [4]. Treatment includes initiation of a gluten-free diet as well as immunomodulatory therapy. A clinical response was observed in 24 (80%) patients after treatment with combination of a gluten-free diet and immunosuppressants, whereas 9 and 5 patients had histologic improvement and complete remission, respectively.Figure: [877]