Idiopathic Granulomatous Appendicitis Treated Surgically with Long-Term Follow-Up: Report of a Case

Abstract

Isolated granulomatous inflammation of the appendix is extremely rare, and its etiology is still unknown. Thus, differentiating between idiopathic granulomatous appendicitis and isolated appendiceal Crohn's disease is difficult. We report a case of idiopathic granulomatous appendicitis with long-term follow-up after surgery. A 26-year-old woman was referred to our hospital for investigation of persistent right lower abdominal pain. Abdominal computed tomography showed a mass, suggesting an inflammatory tumor around the appendix; thus, we suspected subacute appendicitis and performed laparoscopically assisted ileocecal resection. Histological examination of the resected specimen revealed several noncaseous epithelioid granulomas in the wall of the appendix, but no foreign bodies, obstructing lesions, or parasites. Stains for acid-fast bacillus and fungi, and serology for yersinia were all negative. The patient has been followed up for 9 years and remains asymptomatic. This clinical course suggests that her isolated granulomatous appendicitis was idiopathic granulomatous appendicitis unrelated to Crohn's disease.

Granulomatous appendicitis in a 12-year-old boy

“…Distinguishing idiopathic GA and isolated appendiceal Crohn's disease is difficult in the perioperative period. The prognosis of idiopathic GA appears to be favorable [2][3][4]21]. In our patient, granulomas (composed of epithelioid histiocytes with central necrosis) were demonstrated in the wall of appendix; but no definitive cause was detected after investigations.…”

“…Although granulomas are a manifestation of Crohn's disease, only 5% to 10% of patients with GA develop Crohn's disease elsewhere in their gastrointestinal tract [2]. There are 2 types of isolated granulomatous inflammation of the appendix, namely, idiopathic GA and isolated appendiceal Crohn's disease [4].…”

“…Granulomatous appendicitis is a rare condition, accounting for less than 2% of all cases of appendicitis [2,16]. The reported incidence in Western countries ranges from 0.14% to 0.3%, with an incidence of 1.3% to 2.3% in developing countries [17].…”

“…Unusual causes include sarcoidosis; foreign body reaction; and infection by mycobacteria, fungi, or parasites. These conditions combined explain less than 10% of the patients [2]. Infectious and noninfectious causes have been responsible for 62% and 38% of GA, respectively.…”

Granulomatous appendicitis in children: A single institutional experience

“…Few case series in adult population have reported the incidence of GA between 0.14% and 2% of appendectomies. [1][2][3] There are only anecdotal case reports [4,5] with no real cohort study of GA in children hitherto; clearly mentioning the incidence, or specific characteristics. We made an attempt to determine the incidence and characteristics of the cases of GA operated in children at a single tertiary care institution.…”