U Ihedioha, J Coldewey, D Murphy
Department of General Surgery, Monklands Hospital, Airdrie
Correspondence to: Dr U C Ihedioha, Dept of General Surgery, Monklands Hospital, Monkscourt Avenue, Airdrie, ML6 0JS E-mail: ugoihedioha@hotmail.com
SMJ 2004 49(4): 157-158
Inflammatory pseudotumors of the caecum are uncommon. They pose problems with diagnosis. We report on a 35 year old female who presented with clinical signs of acute appendicitis. Intra-operatively, a caecal tumour was found with normal appendix and multiple enlarged mesenteric lymph nodes. A right hemicolectomy was performed. Histopathology findings revealed an inflammatory mass with abundant fibroblast proliferation with associated collagen formation, infiltrating bowel wall and pericaecal adipose tissue. She recovered well and was discharged home 5 days post-operatively. At present, she is free of symptoms.
Key words: Inflammatory pseudotumour, caecal tumour
Inflammatory pseudotumors, also referred to as inflammatory myofibroblastic tumours, are rare nonneoplastic, fibrosing inflammatory lesions that can be found in several organs of the body.7 They are primarily composed of chronic inflammatory cells in association with proliferating mesenchymal cells and collagen deposition. There are uncertainties concerning their aetiology, clinical presentation and investigation modalities for a definite pre-operative diagnosis. Most patients present with varied symptoms which include fever, abdominal pain, vomiting, chills, jaundice and weight loss. Resection of these tumors seems to be diagnostic as well as curative. Three cases of inflammatory pseudotumor involving the caecum were previously described,3,5,6 To our knowledge, there are no other reports of this tumour affecting the caecum. We report a case of inflammatory pseudotumor of the caecum.
A 35 year old woman presented with a one day history of severe right iliac fossa pain. There was associated history of nausea, vomiting and fever. Her past medical history was unremarkable except for having similar pains on and off for several months. On clinical examination, she was pyrexial with tenderness and guarding at the right iliac fossa. There was associated rebound tenderness. Her haematology profile, renal and liver function tests were normal.
Plain abdominal x-ray revealed some slightly dilated loops of small bowel.(Fig 1) Transvaginal and transabdominal scans showed normal pelvic organs with some free fluid measuring approximately 3.0 cm in the Pouch of Douglas. There were no adnexial masses noted. The clinical suspicion was that of an acute appendicitis.
At laparotomy, the appendix was normal but there was a 4cm mass involving the caecum with enlarged mesenteric lymph nodes. An operative diagnosis of caecal carcinoma was suspected and a right hemicolectomy was carried out to remove the mass. The liver was noted to be clear of tumour infiltrates with no other abnormalities found. Histopathology of the mass revealed an inflammatory mass with abundant fibroblast proliferation with associated collagen formation, infiltrating bowel wall and pericaecal adipose tissue.( Fig 2a) In some areas, ( Fig 2b ) adipose cells could be seen entrapped by a spindle cell proliferation, with collagen deposition and variably dense mixed inflammatory cell infiltrate elsewhere. The patient had an uneventful post-operative recovery, being discharged five days post-operatively.
Inflammatory pseudotumors of the caecum are uncommon mesenchymal neoplasms with a variable histologic appearance. They are composed of proliferating myofibroblasts accompanied by a prominent infiltrate of chronic inflammatory cells, particularly plasma cells. This feature best distinguishes these lesions from fasciitis and fibromatosis, with which they overlap.2,4 They are rare in the caecum and constitute major diagnostic dilemma. They affect mostly young people3 and present with a mass with or without constitutional symptoms such as fever, weight loss, nausea and vomiting. Our patient presented with symptoms of acute appendicitis.
It has been postulated that pseudotumors are associated with a variety of infectious agents including Epstein –Barr virus, Actinomyces, Pseudomonas species, Mycoplasma, and Human herpes virus.2 There was no history suggestive of an inflammatory process in our patient and routine haematologic and radiologic investigations gave no clues as to the possible cause. The differential diagnosis include Crohn’s disease, tuberculosis, amebiasis, actinomycosis, diverticulitis, idiopathic caecal ulcers, fibroid polyps, foreign bodies reaction, localized pseudomembranous colitis, lymphoid polyps and sclerosing mesenteritis.6 Histopathology confirms the diagnosis.
Inflammatory myofibroblastic tumour cannot be distinguished clinically from highly malignant neoplasm or some other conditions. Surgical resection and careful histopathological analysis are needed. From a prognostic perspective, pseudotumors are soft tissue mesenchymal tumours of indeterminate or low malignant potential.3 They have a potential to reoccur. Complete excision is the ideal treatment. Features which are associated with a higher recurrence risk are intra-abdominal, omental, mesenteric or retroperitoneal location; proximity to vital structures and multinodularity.1 In this case, the tumour was intraabdominal for which a right hemicolectomy was performed.
In summary, pseudotumors of the caecum are rare. Their aetiology is not readily apparent. We advocate a right hemicolectomy for patients presenting with this tumour in the caecum so as to prevent recurrence.
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