Extracolonic gastrointestinal tract morphologic findings in a case of pseudomembranous collagenous colitis

Area of Science:

• Gastroenterology
• Pathology

Background:

• Collagenous colitis is a condition characterized by a thickened subepithelial collagen layer in the colon.
• Pseudomembranous collagenous colitis (PCC) is a morphologic variant with prominent inflammation and pseudomembranes, linked to various etiologies.
• Extracolonic manifestations of PCC have not been previously detailed.

Observation:

• A case study of a patient with PCC exhibiting unusual extracolonic findings is presented.
• Histologic examination revealed gastric antral mucosa with features suggestive of ischemic injury.
• Duodenal and ileal biopsies showed reactive gastropathy with intraepithelial lymphocytosis and partial villous atrophy.

Findings:

• The extracolonic findings in this PCC case included gastric and small intestinal mucosal abnormalities.
• Small intestinal biopsy findings mirrored those observed in conventional collagenous colitis.
• Pathologic findings underscore the clinical and histological overlap between PCC and conventional collagenous colitis.

Implications:

• This case expands the understanding of the potential extracolonic pathology associated with pseudomembranous collagenous colitis.
• The observed similarities suggest a potential shared pathogenetic mechanism between PCC and conventional collagenous colitis.
• Further research may clarify the clinical significance and diagnostic implications of these extracolonic findings.