Looking down at the path report that read "Wild type gastrio-intestinal stormal tumor", I had to reach deep into my memories of adult general surgery training, and all I could come up with was Gleevec. Clearly not enough to formulate a management plan for my 12 year old patient.
Off to Pubmed...
Talk about children not being just small adults! Pediatric GISTs, it turns out, are a whole different animal.
Adult GISTs are tumors of mesenchymal origin that carry a tyrosine kinase receptor activating mutation. 85% of tumors in adults will have a mutation in either oncogenic KIT, PDGRRA, or (less commonly) BRAF. The presence of a tyrosine kinase mutation is the basis for tumor response to tyrosine kinase inhibitors such as Imatinib (Gleevec).
The pediatric counterpart, a rare entity, differs in a critical way; namely the absence of a tyrosine kinase mutation in the majority (>90%) of cases. Gastrointestinal stromal tumors with no tyrosine kinase mutation are referred to as wild type GISTs. The absence of these mutations translates to the lack of efficacy of tyrosine kinase inhibitors such as Imatinib. Essentially, no effective neo-adjuvant or adjuvant therapy is available for WT GISTs.
Because of the rare nature of GISTs in children, we do not have a clear idea about behavior. The general impression is that these are insidious lesions, that grow slowly and have a high recurrence rate, even in the setting of complete surgical resection.
What does this mean for us, the pediatric surgeons faced with the responsibility of primum non nocere? this is a chronic disease that needs management and not cure; more like hypertension that appendicitis. So avoid big morbid resections if possible, and plan for this disease coming back.
Reference:
Pediatric Gastrintestinal stromal tumor
Off to Pubmed...
Talk about children not being just small adults! Pediatric GISTs, it turns out, are a whole different animal.
Adult GISTs are tumors of mesenchymal origin that carry a tyrosine kinase receptor activating mutation. 85% of tumors in adults will have a mutation in either oncogenic KIT, PDGRRA, or (less commonly) BRAF. The presence of a tyrosine kinase mutation is the basis for tumor response to tyrosine kinase inhibitors such as Imatinib (Gleevec).
The pediatric counterpart, a rare entity, differs in a critical way; namely the absence of a tyrosine kinase mutation in the majority (>90%) of cases. Gastrointestinal stromal tumors with no tyrosine kinase mutation are referred to as wild type GISTs. The absence of these mutations translates to the lack of efficacy of tyrosine kinase inhibitors such as Imatinib. Essentially, no effective neo-adjuvant or adjuvant therapy is available for WT GISTs.
Because of the rare nature of GISTs in children, we do not have a clear idea about behavior. The general impression is that these are insidious lesions, that grow slowly and have a high recurrence rate, even in the setting of complete surgical resection.
What does this mean for us, the pediatric surgeons faced with the responsibility of primum non nocere? this is a chronic disease that needs management and not cure; more like hypertension that appendicitis. So avoid big morbid resections if possible, and plan for this disease coming back.
Reference:
Pediatric Gastrintestinal stromal tumor
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