Figure 1
Abdominal US of the RLQ. Longitudinal view.
Granulomatous appendicitis: a unknown and unusual cause of appendicitis
SectionAbdominal imaging
Case TypeClinical Cases
AuthorsSilva AC, Venâncio J, Ribeiro MJ.
Connected authors
33 years, female
Clinical History
A 33 year old female was admitted with subacute abdominal pain more prominent in the righ lower quadrant.
Imaging Findings
A 33 year old woman presented with subacute abdominal pain localized in the RLQ, anorexia and low grade fever for the last 72 hours.
Physical examination revelead a tenderness in the right flank. Blood testes showed CRP of 24 mg/L and leuckocytosis of 12000 mm3. An abdominal and pelvic ultrasound was preformed (Fig. 1, 2).
What is the diagnosis? Does the inflamed appendix has any particularly characteristics or does it look like an ordinary acute appendicitis? The ultrasound exam using a graded compression technique (1) shows a markedly distended, non-peristaltic, non-compressible blind-ending pouch with origin in the medial aspect of the cecum. Its maximal short diameter was of 23 mm and the appendicular wall measured approximately 7 mm. The diagnosis of acute appendicitis was made on the clinical and imaging findings.
However due to a rather atypical clinical presentation, the presence of marked thickened wall and pericecal adenopathy other diagnosis like appendicular carcinoma or granulomatous appendicitis was considered.
Abdominal computed tomography was therefore performed (Fig. 2, 3) showing a marked thickened appendix, with an endoluminal fecalith.
Moderate fat stranding was present as well as pericecal and periappendicular lymphadenopathy.
An ileocolectomy was preformed. Pathology revealed the presence of a chronic transmural inflammation with lymphoid aggregates and germinative centers (Fig 3, arrow). Epitheliod granulomas and multinucleate giant cells were seen (Fig 4, arrow). Microscopy of adjacent nodes revealed the presence of the same chronic granulomatous inflammatory process (Fig. 6). The final diagnosis of idiopathic granulomatous appendicitis was made.
Physical examination revelead a tenderness in the right flank. Blood testes showed CRP of 24 mg/L and leuckocytosis of 12000 mm3. An abdominal and pelvic ultrasound was preformed (Fig. 1, 2).
What is the diagnosis? Does the inflamed appendix has any particularly characteristics or does it look like an ordinary acute appendicitis? The ultrasound exam using a graded compression technique (1) shows a markedly distended, non-peristaltic, non-compressible blind-ending pouch with origin in the medial aspect of the cecum. Its maximal short diameter was of 23 mm and the appendicular wall measured approximately 7 mm. The diagnosis of acute appendicitis was made on the clinical and imaging findings.
However due to a rather atypical clinical presentation, the presence of marked thickened wall and pericecal adenopathy other diagnosis like appendicular carcinoma or granulomatous appendicitis was considered.
Abdominal computed tomography was therefore performed (Fig. 2, 3) showing a marked thickened appendix, with an endoluminal fecalith.
Moderate fat stranding was present as well as pericecal and periappendicular lymphadenopathy.
An ileocolectomy was preformed. Pathology revealed the presence of a chronic transmural inflammation with lymphoid aggregates and germinative centers (Fig 3, arrow). Epitheliod granulomas and multinucleate giant cells were seen (Fig 4, arrow). Microscopy of adjacent nodes revealed the presence of the same chronic granulomatous inflammatory process (Fig. 6). The final diagnosis of idiopathic granulomatous appendicitis was made.
Discussion
Idiopathic granulomatous appendicitis is a distinct pathological entity unrelated to granulomatous ileocolitis with pathognomonic features in pathology [2].
It has a slight male predominance. It can present acutely, being indistinct from acute appendicitis, however it can also have a more indolent and subacute presentation [3] making its clinical diagnosis more difficult.
Although this is a rare condition occurring in 0,9% of all appendectomies it has characteristics features at CT that allow its recognition. Namely the presence of a markedly enlarged appendix, a marked thickened and poorly defined appendicular wall, (with loss of layer differentiation when intravenous contrast is administrated giving the appearance of a soft tissue mass), the presence of a disproportionately moderate fat stranding surrounding the appendix (less pronounced that one would expect if we were facing an acute inflammatory process) and finally the presence of loco regional adenopathy.
Although these findings are suggestive of granulomatous appendicitis they do not exclude other rare but more sinister diagnosis as appendicular lymphoma or appendicular adenocarcinoma. Therefore a confident pre-operative diagnosis is seldom done being the definitive diagnosis almost invariably done by pathology.
It has a slight male predominance. It can present acutely, being indistinct from acute appendicitis, however it can also have a more indolent and subacute presentation [3] making its clinical diagnosis more difficult.
Although this is a rare condition occurring in 0,9% of all appendectomies it has characteristics features at CT that allow its recognition. Namely the presence of a markedly enlarged appendix, a marked thickened and poorly defined appendicular wall, (with loss of layer differentiation when intravenous contrast is administrated giving the appearance of a soft tissue mass), the presence of a disproportionately moderate fat stranding surrounding the appendix (less pronounced that one would expect if we were facing an acute inflammatory process) and finally the presence of loco regional adenopathy.
Although these findings are suggestive of granulomatous appendicitis they do not exclude other rare but more sinister diagnosis as appendicular lymphoma or appendicular adenocarcinoma. Therefore a confident pre-operative diagnosis is seldom done being the definitive diagnosis almost invariably done by pathology.
Differential Diagnosis List
Idiopathic granulomatous appendicitis.
Final Diagnosis
Idiopathic granulomatous appendicitis.
References
[1] Puylaert JB (1986) Acute appendicitis: US evaluation using graded compression. Radiology 158(2):355-60. (PMID: 2934762)
[2] Allen DC, Biggart JD (1983) Granulomatous disease in the vermiform appendix. J Clin Patholol 36:632-638. (PMID: 6853730)
[3] Zissin R, Gayer G, Bernheim E, Kots E, Shapiro-Feinberg M, Herts M (2003) Granulomatous appendicitis presenting as right lower quadrant pain: CT findings. Abdom Imaging 28:280-283. (PMID: 12592479)
Case information
| URL: | https://www.eurorad.org/case/7104 |
| DOI: | 10.1594/EURORAD/CASE.7104 |
| ISSN: | 1563-4086 |
Figure 2
Abdominal US of the RLQ. Transversal view.
Figure 3
Axial CECT scan. The arrow points to the pathological appendix.
Figure 4
Axial CECT scan. The arrow points to the pathological appendix.
Figure 5
Microscopy at a lower magnification.
Figure 6
Microscopy of the appendix at a higher magnification (200x).
Figure 7
Microscopy of the lymph nodes.
Abdominal US of the RLQ. Longitudinal view.
Abdominal US of the RLQ. Transversal view.
Axial CECT scan. The arrow points to the pathological appendix.
Axial CECT scan. The arrow points to the pathological appendix.
Microscopy at a lower magnification.
Microscopy of the appendix at a higher magnification (200x).
Microscopy of the lymph nodes.
