Diagnosis: tubular carcinoid of appendix and acute appendicitis.
Discussion: the remaining specimen was submitted into 20
additional cassettes, but no tumor was seen in these sections.
The tumor is confined to the submucosa and superficial
muscularis propria and present in only one section measuring 3.5
mm in maximum dimension. This tumor is a type of mixed
exocrine-endocrine tumor of appendix which also includes goblet
cell carcinoids and mixed carcinoid-adenocarcinoma.
Histologically the tumor in this case shows no goblet cell
differentiation and no classic adenocarcinoma features. It is
composed of small glands and tubules interspersed amongst smooth
muscle bundles of the appendiceal wall. No cytologic atypia
(beyond typical neuroendocrine lesion) is seen. According to the
literature (see reference) tubular carcinoids are behaving in a
Reference: Capella C et al. Endocrine tumours of the appendix.
In Hamilton SR and Aaltonen LA (Editors): WHO Classification of
Tumours. Pathology and Genetics Tumours of the Digestive System.
IARC Press, Lyon 2000:99-101.