Title : An unusual cause of duodenal cobblestoning: Monomorphic epitheliotropic intestinal T-cell lymphoma presenting with protein-losing enteropathy
Abstract:
Background: Duodenal cobblestoning is typically associated with inflammatory conditions such as Crohn’s disease and rarely with intestinal lymphoma. Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare, aggressive primary intestinal T-cell lymphoma that typically affects the jejunum and ileum and often presents with non-specific gastrointestinal symptoms, such as change in bowel habit and abdominal pain. Endoscopic findings are variable and may delay diagnosis.
Case Presentation: A woman in her 70s presented with progressive generalised oedema, unintentional weight loss, hypoalbuminaemia, and mild iron-deficiency anaemia. CT thorax-abdomen-pelvis demonstrated extensive subcutaneous oedema, ascites, bilateral pleural effusions, and diffuse small bowel thickening, raising concern for a protein-losing enteropathy. Urinalysis, echocardiography, and coeliac serology were unremarkable.
Gastroscopy revealed grade 1 oesophagitis, an oedematous gastric body and cobblestoning of the duodenal mucosa. Differential diagnoses included Crohn’s disease, lymphoid hyperplasia, and Brunner gland hyperplasia. Histological examination of duodenal biopsies demonstrated diffuse intraepithelial infiltration by monomorphic small-to-intermediate lymphoid cells without villous atrophy or crypt hyperplasia. Immunohistochemistry showed positivity for CD3, CD8, and CD56, loss of CD5 expression, and negativity for CD20, CD10, CD30, and CD4. The Ki-67 proliferation index was approximately 50%. Next-generation sequencing demonstrated clonal T-cell receptor rearrangements across TRA, TRB, and TRG loci, confirming a diagnosis of monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL).
Following multidisciplinary discussion, the patient received anthracycline-based chemotherapy (CHOP). Despite initial treatment, she subsequently developed malignant bowel obstruction and was not a candidate for surgical intervention. Unfortunately, she sadly passed away several months after diagnosis.
Discussion: MEITL accounts for less than 5% of T-cell lymphomas and carries a poor prognosis. Unlike enteropathy-associated T-cell lymphoma, it is not associated with coeliac disease. Endoscopic appearances are variable, depending on disease progression. Mucosal oedema with nodularity, shallow ulcerations, diffuse erosions, and duodenal cobblestoning, which can mimic inflammatory bowel disease. Recognition of atypical endoscopic findings and early biopsy with immunophenotypic and molecular analysis are essential for timely diagnosis.
Conclusion: MEITL should be considered in the differential diagnosis of unexplained duodenal cobblestoning, particularly in patients presenting with protein-losing enteropathy and severe hypoalbuminaemia. Early histological assessment is critical given the aggressive nature and poor outcomes associated with this rare lymphoma.
