An Enigmatic Entity – Idiopathic Granulomatous Appendicitis

Abstract

Purpose: Granulomatous appendicitis (GA) is a rare condition occurring in 0.1% to 2% of all appendectomies. Possible etiologies of GA include Crohn's disease (CD), sarcoidosis, foreign body reaction, obstruction caused by fecalith, mucocele or tumor and infectious agents such as mycobacterium, fungi and parasites. Idiopathic granulomatous appendicitis (IGA) is an extremely rare condition with unknown etiology. Methods: A 29-year-old male presented with complain of right lower quadrant (RLQ) pain for 6 months. In addition, patient had nausea, vomiting, diarrhea, fever and chills. Results: On abdominal examination, localized tenderness present in the RLQ with positive rebound. On laboratory investigation, patient had leukocytosis with normal hemoglobin, amylase and lipase. Patient was admitted for same episodic complaint 6 months and 4 months prior; perforated appendix with peritonitis was diagnosed at those times, but patient refused surgery. He was treated with oral antibiotics and advised to follow-up in surgery clinic. The patient now presented with same complain. Intravenous antibiotics were started; CT scan revealed phlegmon in RLQ. Patient underwent laparoscopic appendectomy. On laproscopy, there were local chronic inflammatory process with fibrosis and adhesion on the lateral wall, which complicated the procedure. Therefore, open laprotomy was attempted. Appendix and cecum was inflamed so appendectomy was completed along with right hemicolectomy and terminal ileactomy. Biopsy of appendix revealed focal ulceration, mucosal necrosis, transmural acute and chronic inflammation with crypt abscess, and multiple small non-necrotizing granulomas with multinucleated giant cells in lamina propria, submucosa and muscularis mucosa. Stain for fungal, acid fast bacilli and Yersinia organisms were negative. Histopathology of right colon and terminal ileum revealed scattered inflammatory cell infiltrate without evidence of cryptitis, crypt abscess or granuloma. Mesenteric lymph nodes showed benign acute and chronic inflammatory infiltrate. Patient was discharged without further episodes. Conclusion: IGA is an extremely rare condition with unknown etiology, though it is theorized that it may be associated with recurrent and subacute appendicitis. Recurrent appendicitis produces granulomatous reaction secondary to inflammation. Use of temporary treatment, such as antibiotics, delays the need for appendectomy, but may inclrease chances of developing IGA. IGA was initially thought to be part of the Crohns Disease spectrum, but recent studies show that IGA has different histopathological features than CD and that only 5 to 10% of IGA patients eventually developed CD. IGA should be considered in cases that mimic the illness course described here.