Sections of the small bowel show a dense, transmural chronic inflammatory infiltrate composed of a polymorphic population of mature lymphocytes, plasma cells, and histiocytes interspersed with prominent fibroblastic proliferation, with relatively preserved tissue architecture.
Immunostaining was done with appropriate positive and negative controls and revealed a polyclonal distribution of inflammatory cells, with CD20 highlighting reactive B-cell follicles and CD3 marking a population of interspersed T-cells; CD43 shows normal T-cell positivity with no evidence of aberrant co-expression in B-cells, while CK staining is restricted to the intestinal mucosal epithelium.
Referred blocks for immunostaining of annular strictures causing small bowel obstruction.
Four referred paraffin blocks.
Immunostaining of Small bowel, resection: