The Gist of Literature on Pediatric GIST

Abstract

To provide a review of existing literature on pediatric GIST with focus on clinical presentation. A MEDLINE search was conducted in July 2007 to give an overview on literature concerning pediatric gastrointestinal stromal tumors (GISTs) with a focus on clinical presentation, using keywords "gastrointestinal stromal tumor" and one of the following "young/boy/girl/child/children/pediatric." Two of the authors sorted the resulting abstracts by relevance for a review on clinical aspects of pediatric GIST if they were in English language, not explicitly only reporting of adults and describing clinical features of patients. One hundred and six articles were found, 43 of which were excluded because they did not match the criteria mentioned above. We found 97 patients in the articles meeting our criteria, of which 38 cases had to be excluded, because of lacking clinical data, negative staining for CD117 or syndromal occurrence. This left 59 patients for analysis of clinical symptoms in the presentation of nonsyndromal CD117-positive GIST in children. Clinical feature most frequent was anemia in 86.4% (n=51) symptomatic either through acute or subacute bleeding. There was no palpable tumor in 88.1% (n=52), no abdominal pain in 84.7% (n=50), and no vomiting in 88.1% (n=52). Girls tend to show more high-grade tumors and existing case reports show a 2.7-fold higher incidence in females. Altogether epithelioid cell tumors are most frequent, although in boys spindle-cell tumors are reported more often. On the basis of National Institute of Health criteria (6) tumors were low grade in 22% (n=13), medium grade in 37.3% (n=22), and high grade in 35.6% (n=21). There were more high-grade tumors in girls than in boys (40.5% vs. 28.6%). Local excision was the operation most often performed, but details of surgery were missing in most cases. Pediatric GIST is a rare but considerable diagnosis in chronic anemia, which is the most frequent clinical finding with this tumor entity. Recent review articles focus on histopathologic criteria but omit clinical features and course of disease. In nonsyndromal CD117-positive GIST, girls tend to show more high-grade tumors and existing literature on pediatric GIST shows a 2.7-fold higher incidence in females. Altogether epithelioid cell tumors are most frequent, although in boys spindle-cell tumors are reported more often. Together with known differences in molecular changes and local as well as systemic tumor behavior this strongly suggests that pediatric GIST represents a different entity than adult GIST. After establishment of clear-cut pathologic features in the past, reports on preoperative diagnostic findings, long-term follow-up, and therapy have to be emphasized to clarify the relationship of these entities.