Mesenteric tumour deposits arising from small-intestine neuroendocrine tumours are frequently associated with fibrosis and IgG4-expressing plasma cells.

Journal Article (Journal Article)

AIMS: Mesenteric tumour deposits frequently occur in small-intestine neuroendocrine tumours. In many instances, these mesenteric tumour deposits are surrounded by a dense fibrotic stroma and have associated lymphoplasmacytic inflammation. The aim of this study was to examine whether mesenteric tumour deposits in patients with small-intestine NETs neuroendocrine tumours show histological and immunophenotypic overlap with IgG4-related sclerosing mesenteritis. METHODS AND RESULTS: Sixty-six mesenteric tumour deposits from 66 patients with small-intestine neuroendocrine tumours with blocks available for further studies were identified from our archives. Cases were assessed for clinicopathological features and the presence of IgG4-positive and IgG-positive plasma cells by immunohistochemistry. Ratios of IgG4-positive to IgG-positive plasma cells were calculated. Seventeen mesenteric tumour deposits (26%) showed >40 IgG4-positive plasma cells per high-power field, and the majority of cases (68%) showed at least some staining of IgG4-positive plasma cells. Mesenteric tumour deposits with >20 IgG4-positive plasma cells per high-power field tended to be larger (25.9 ± 13.0 mm versus 18.6 ± 15.8 mm; P = 0.07), and had more IgG-positive plasma cells (88 ± 24 versus 36 ± 37; P < 0.01) and a higher IgG4-positive/IgG-positive plasma cell ratio (0.66 ± 0.18 versus 0.17 ± 0.25; P < 0.01). All but one mesenteric tumour deposit with >20 IgG4-positve plasma cells had a ratio of >40%. CONCLUSIONS: IgG4 expression is frequent in mesenteric tumour deposits from small-intestine neuroendocrine tumours. Undersampling of tumour on biopsies of mesenteric tumour deposits could potentially cause diagnostic confusion with IgG4-related sclerosing mesenteritis.

Full Text

Duke Authors

Cited Authors

  • Roberts, J; Gonzalez, RS; Revetta, F; Shi, C

Published Date

  • November 2018

Published In

Volume / Issue

  • 73 / 5

Start / End Page

  • 795 - 800

PubMed ID

  • 29943407

Pubmed Central ID

  • PMC6197921

Electronic International Standard Serial Number (EISSN)

  • 1365-2559

Digital Object Identifier (DOI)

  • 10.1111/his.13693


  • eng

Conference Location

  • England