Introduction:
Eosinophilic enteritis (EE) is an extremely rare disease, involving the entire gastrointestinal tract (GIT),
although stomach and duodenum are frequently involved sites.1 The pathogenesis and etiology of eosinophilic enteritis remains unclear.1
Appendix is rarely involved by this entity.
Acute appendicitis is one of the most common surgical disease worldwide. It is primarily diagnosed on the basis of
history and the physical examination with additional assistance from laboratory and radiographic findings.2 Currently the most accepted
explanation for the development of acute appendicitis is obstruction and secondary infection.3 The obstruction is thought to be due to
extra luminal adhesions or luminal causes such as faecoliths or lymphoid hyperplasia in the walls3 or rarely as a result of the infective
process. Primary obliterative appendicitis due to eosinophils in the absence of faecoliths or lymphoid hyperplasia is a rare clinical entity.
Herein, we report a case of primary eosinophilic obliterative appendicitis, which is an extremely uncommon clinical
entity.
Case Report:
A twenty five years old male presented with chief complaints of recurrent pain in right iliac fossa just below
the umbilicus. It was not associated with fever, vomiting or diarrhoea. There was no family history of allergy or atopy and no history of drug allergy, asthma or allergic rhinitis.
Local examination revealed mild to moderate tenderness in right iliac fossa. Rest of systemic examination was not contributory. Routine hematological examination showed
hemoglobin 12gm%, total leucocyte count 13100/cmm and differential count of neutrophils 80%, lymphocytes 13%, and eosinophis 3%. Other biochemical and serological examination were unremarkable.
The patient was clinically diagnosed as appendicitis and open appendicectomy was performed under general anesthesia and resected specimen was sent
for histopathological examination. Post-operative period was uneventful and patient was fine on regular follow up.
Gross features: The appendicectomy specimen measured 5.5cm in length. External surface showed congested blood
vessels and covered with grey-brown areas of thick exudates. On cut section showed obliteration of the lumen and thickened wall was seen.
The obliterated lumen show grey whitish appearance.
Light microscopy: Multiple section studied shows appendix. Mucosa showed extensive areas of ulcerative and denuded
epithelium (Fig. 1). Submucosa showed necrotic areas, congestion and oedema. All the layers including muscular propria showed dense and diffuse
infiltration by eosinophils that was >25-50/hpf (Fig. 2). All the layers showed congestion and serosa showed fibrosed walls with dense, diffuse
eosinophilic infiltration. Final histopathological diagnosis was given as Primary eosinophilic obliterative appendicitis.
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Figure 1: Photomicrograph of appendicular mucosa showed extensive ulceration of the epithelium with mild dense, diffuse infiltration of eosinophils in all layers (H & E, x100). |
Figure 2: Photomicrograph showing muscularis propria with dense and diffuse infiltration by eosinophils (H & E, x400). |
Discussion:
Primary eosinophilic appendicitis (EA) primarily affects the appendix with eosinophil rich transmural inflammation
in excess of 10 per cmm (more than 25 eosinophils per high power field) in muscularis mucosa with absence of polymorphs or any other pathology in
the wall as per Carr NJ4, with no known cause for eosinophilia including drug reaction, parasitic infections and malignancy.5
Primary eosinophilic obliterative appendicitis is a rare clinical entity. The cause for obstruction of the
appendicular lumen may vary as inflammatory stricture, appendicolith, villous adenoma, carcinoid tumour, mucosal web, endometriosis, carcinoma and
extrinsic compression or inflammatory process. Usually a specific cause of obstruction may not be found as documented by Rokitansky CF.6
Eosinophilic appendicitis may present as obstruction or rarely as mucocele7 or eosinophilic edema.8
Depending upon the involvement of different layers of intestinal wall, symptoms may vary. The mucosal form of
eosinophilic appendicitis, the most common variant, is characterized by vomiting, abdominal pain, diarrhoea, blood loss in stools, iron deficiency
anemia and malabsorption. The muscularis form is characterized by infiltration of eosinophils predominantly in the muscle layer leading to
thickening of walls due to fibrosis, resulting in obliterative appendicitis. This may have happened in our case. Serosal form is characterized by
exudative ascites.9 Carr NJ4 suggests that an eosinophil count in excess of 10 per cmm (25 per 10 HPF) could be abnormal
and labelled as eosinophilic appendicitis. Our case fulfilled these criteria. In our case, eosinophils were present in all the layers including
muscularis propria (25-50 per HPF) leading to obliteration of lumen due to muscular fibrosis.
The pathogenesis and etiology of the disease is not well understood, hence no standard for the diagnosis of
eosinophilic appendicitis exists. Tally et al9 have identified three main diagnostic criteria for EE as:
- Presence of gastrointestinal symptoms
- Biopsies demonstrating eosinophilic infiltration of one or more sites of GIT.
- No evidence of parasitic or extrinsic disease.
In our case, all the criteria were fulfilled. Peripheral eosinophilia was not noted in our case. Stool and upper
and lower gastrointestinal scopy in our case was not significant. As per Tally et al9, in 80% of the cases peripheral eosinophilia was
noted. However gold standard of EE and EA requires histopathological evidence of eosinophilic infiltration.7,9
Mainstay of treatment is surgical intervention when complication as obstruction was evident. Steroids,
sodium chromoglycate, ketotifen, montelukast may be medical alteratives.
Conclusion:
Primary eosinophilic obliterative appendicitis is a rare clinical entity with unexplained symptoms. Surgeons should think of
this condition in differential diagnosis of abdominal pain. Histopathology is the gold standard for diagnosis of this rare condition.
References:
- D'Souza C, Bhagwan KR, Sunil H, Mohan R. Unusual case of subacute intestinal obstruction due to eosinophilic enteritis with enterocolitis. Ann Trop Med Public Health. 2010;3:83-85.
- Nabipour F. Histopathological feature of acute appendicitis in Kerman-Iran from 1997 to 2003. American Journal of Environmental Sciences. 2005;1(2):130-132.
- Arvindan KP. Eosinophils in acute appendicitis: possible significance. Indian J. Pathol. Microbiol. 1997;40(4):491-498.
- Carr NJ. The Pathology of acute appendicitis. Ann Diag Pathol. 2002;4:46-58.
- Rothenberg ME. Eosinophilic gastrointestinal disorders (EGID). J Allergy Clin Immunol. 2004;113:11-28.
- Rokitansky CF. A manual of Pathological anatomy. English translation of the Vienna edition.1982. vol 2. Philadelphia. Blan card and Lea. 1885:89.
- Jagtap SV, Nikumbh DB, Kshirsagar AY, Kanetkar SR, Bohra A. Eosinophilic appendicitis presented as mucocele: A rare clinical entity. IJHSR. 2012;2(2):99-103.
- Aravindan KP, Deepthy V, Marie TM. Acute eosinophilic appendicitis and the significance of eosinophil-Edema lesion. Indian J Pathol Microbiol. 2010;53(2):258-261.
- Talley NJ, Shorter RG, Phillips SF, Zinsmeister AR. Eosinophilic gastroenteritis: A clinicopathological study of patients with disease of the mucosa, muscle layer, and subserosal tissues. Gut. 1990;31:54-58.
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