Histology Course S I 8 Department of Pathology, University of Zurich Histokurs

S I 8 endocrine tumor (carcinoid) of the ileum  IHC: SP further information (German) on HiPaKu
  ICD-10: C17.2; ICD-O: 8240/3

46-year-old female with melaena. The CT scan reveals small tumour in the middle part of the ileum. Partial resection of the ileus.

- The specimen originates from the small bowel wall with parts of a Peyer`s patch.
- At one point a tumour is expanding within the submucosa, which consists of irregularly shaped cell groups. The tumour is well demarcated but infiltrates the innermost layers of the muscularis propria as well as the mucosa, which is ulcerated at the centre of the tumour.
-The individual tumour groups are made up by notably regular population of cells of moderate size and low mitotic activity. Often the cells align at the periphery into palisades.
-Immunohistochemistry stains show the presence of substance P (in a brown reaction product) in many tumour cells and also some disseminated cells of the endocrine system in the normal small bowel mucosa.