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Yersinia appendicitis

Wednesday 26 September 2007


- transmural epithelioid cell granulomas (EPGs)

  • predominantly nonsuppurative
  • surrounded by a lymphoid cuff composed of small lymphocytes.

- suppurative granulomas

  • EPGs with suppuration of the centers of the granulomas (central microabscesses)

- EPGs composed of numerous histiocytes with or without epithelioid cell features, along with scattered small T-lymphocytes and plasmacytoid monocytes.

  • None of the EPGs contain monocytoid B-cells.

Immunohistochemical study

- EPGs usually surrounded by surface IgM/D+ small mantle zone lymphocytes.
- CNA.42 immunostaining occasionally demonstrated residual follicular dendritic cells in the center of the EPGs.


- Yersinia enterocolitica appendicitis (17189675)

Differential diagnosis

- cat scratch disease (numerous monocytoid B-cells)
- lymphogranuloma venerum (numerous monocytoid B-cells)


- Kojima M, Morita Y, Shimizu K, Yoshida T, Yamada I, Togo T, Johshita T. Immunohistological findings of suppurative granulomas of Yersinia enterocolitica appendicitis: a report of two cases. Pathol Res Pract. 2007;203(2):115-9. PMID: 17189675