Histological features of the appendix. (A) Atypical lymphoid cells and preserved lymph follicle are in submucosal layer (H&E stain, ×100). (B) Intraepithelial lymphocytes are not increased, and abnormal tumour cell invasion is not prominent in the mucosal layer (H&E stain, ×200). Large atypical lymphocytes with small distinct nuclei diffusely infiltrate the (C) submucosal layer and (D) eroded lesion. Many reactive histiocytes are seen, mainly in (C) (H&E stain, ×400).
Matsushita and Takeshita Diagnostic Pathology 2013 8:2 doi:10.1186/1746-1596-8-2