Clinical features:
(1) The patient with right lower quadrant pain and other clinical features of appendicitis.
(2) The clinical course is more protracted than what is typical for acute appendicitis.
(3) There is either evidence of Crohn's disease at the time of surgery or it develops later.
Complications may include:
(1) an inflammatory mass in the right lower quadrant
(2) an enterocutaneous fistula
Imaging studies show an enlarged appendix with a markedly thickened appendiceal wall and narrow but patent lumen.
Examination of the appendix shows:
(1) thickening of the appendiceal wall
(2) transmural acute and chronic inflammation
(3) noncaseating granulomas support the diagnosis but are not specific and may be absent
(4) mucosal ulcerations with variable fissures
(5) submucosal and serosal fibrosis
(6) lymphoid hyperplasia
(7) variable crypt abscesses
Differential diagnosis:
(1) idiopathic granulomatous appendicitis
(2) classic acute appendicitis
