Published online Nov 28, 2015. doi: 10.3748/wjg.v21.i44.12713
Peer-review started: June 2, 2015
First decision: June 19, 2015
Revised: July 13, 2015
Accepted: August 30, 2015
Article in press: August 31, 2015
Published online: November 28, 2015
Processing time: 179 Days and 10.5 Hours
This work aims to facilitate diagnosing Aspergillus appendicitis, which can be missed clinically due to its rarity, by proposing a clinical pentad for Aspergillus appendicitis based on literature review and one new case. The currently reported case of pathologically-proven Aspergillus appendicitis was identified by computerized search of pathology database at William Beaumont Hospital, 1999-2014. Prior cases were identified by computerized literature search. Among 10980 pathology reports of pathologically-proven appendicitis, one case of Aspergillus appendicitis was identified (rate = 0.01%). A young boy with profound neutropenia, recent chemotherapy, and acute myelogenous leukemia presented with right lower quadrant pain, pyrexia, and generalized malaise. Abdominal computed tomography scan showed a thickened appendiceal wall and periappendiceal inflammation, suggesting appendicitis. Emergent laparotomy showed an inflamed, thickened appendix, which was resected. The patient did poorly postoperatively with low-grade-fevers while receiving antibacterial therapy, but rapidly improved after initiating amphotericin therapy. Microscopic examination of a silver stain of the appendectomy specimen revealed fungi with characteristic Aspergillus morphology, findings confirmed by immunohistochemistry. Primary Aspergillus appendicitis is exceptionally rare, with only 3 previously reported cases. All three cases presented with (1)-neutropenia, (2)-recent chemotherapy, (3)-acute leukemia, and (4)-suspected appendicitis; (5)-the two prior cases initially treated with antibacterial therapy, fared poorly before instituting anti-Aspergillus therapy. The current patient satisfied all these five criteria. Based on these four cases, a clinical pentad is proposed for Aspergillus appendicitis: clinically-suspected appendicitis, neutropenia, recent chemotherapy, acute leukemia, and poor clinical response if treated solely by antibacterial/anti-candidial therapy. Patients presenting with this proposed pentad may benefit from testing for Aspergillus infection by silver-stains/immunohistochemistry and considering empirical anti-Aspergillus therapy pending a tissue diagnosis.
Core tip: This work reports the fourth reported case of isolated Aspergillus appendicitis, further characterizes this syndrome, and identifies a clinical pentad associated with this syndrome: clinically-suspected appendicitis, neutropenia, recent chemotherapy, acute leukemia, and poor clinical course if treated solely with antibacterial or anti-Candidial antibiotics. These risk factors are biologically reasonable. Immunosuppression from neutropenia and acute leukemia may promote Aspergillus appendicitis. Local gastrointestinal ulcers from recent chemotherapy provides a nidus for fungal colonization. In patients presenting with this proposed pentad, Aspergillus appendicitis should be considered in the differential diagnosis, special silver stains should be performed to evaluate for this infection, and empiric anti-Aspergillus therapy may be considered pending tissue diagnosis.