Abdominal inflammatory masses mimicking neoplasia in children-experience of two centers.

Despite progress in modern imaging, some inflammatory masses are difficult to distinguish clinically from neoplastic processes. In such cases the pathology report has a great distinctive value, but even then the final diagnosis may be difficult to reach. Eight patients with abdominal tumors of inflammatory origin were treated in two institutions, the Department of Pediatric Surgery of the Medical University of Gdansk, Poland, and Helios Center of Pediatric Surgery in Berlin, Germany, during the last 10 years. Four tumors were located in the pelvis, two in the liver, and two in the colonic mesentery. Five of them were inflammatory pseudotumors (two subclassified as inflammatory fibrosarcoma), one had nonspecific inflammatory changes, one was diagnosed as idiopathic retroperitoneal fibrosis, and one was diagnosed as bacillary angiomatosis. All patients underwent surgical tumor biopsy, excisional in four and incisional in four. All but two children underwent macroscopically complete tumor excision (four primarily, two secondarily). In one case the tumor resolved with antibiotherapy. Surgery in retroperitoneal masses was often extensive and associated with significant complications because of invasive tumor growth. In conclusion, intraabdominal inflammatory lesions may closely mimic neoplasia in children. Clinical doubts result in repeated biopsies, and for this reason excisional biopsy should be preferred. In some cases, when excisional biopsy is not feasible due to invasive growth of the tumor, delayed complete mass excision should follow, despite occasional significant morbidity. The etiology and exact nature of inflammatory pseudotumors are still obscure, and it is unknown whether they represent inflammatory lesions or true neoplasia.