weekly_question 25/4/2021

[Admin]

A 12 year old girl presents with anemia and vague abdominal pain. A CT confirms a gastric mass. On exploration, a 8 cm mass of the fundus is encountered.

The most appropriate intervention is:

A Total gastrectomy

B Radiation therapy

C Wedge resection

D Biopsy followed by chemotherapy

E Intraoperative EGD with biopsy

[Admin]

correct answer
C Wedge resection

Gastrointestinal stromal tumors (GIST) are rare soft tissue sarcomas thought to arise from the interstitial cells of Cajal. Most develop within the stomach (60%) or small intestine (30%), but may occur anywhere from the esophagus to the rectum. Pediatric GISTs are exceedingly rare with several distinctions from their adult counterparts. Mutations in KIT and platelet derived growth factor receptor alpha (PDGFRA) have been identified in over 90% of adult patients. However, pediatric patients lack these activating mutations in the receptor tyrosine kinase that drive tumor formation in adults. As such, they are referred to as “wild type” GIST. Interestingly, despite the lack of somatic KIT mutations these tumors still have levels of KIT activity similar to the adult mutant GISTs. Pediatric GISTs may be associated with hereditary syndromes such as Carney triad (GIST, pulmonary chondroma and paraganglioma) and neurofibromatosis type 1. In the Carney-Stratakis dyad (GIST and paraganglioma) germline inactivating mutations have been identified in the succinate dehydrogenase (SDH) genes.

Most pediatric cases present between 10 and 18 years of age. The most frequent clinical feature of pediatric GIST is anemia - symptomatic either through acute or subacute bleeding. No palpable tumor, abdominal pain or vomiting are evident in most cases. Unlike the adult tumors they have a female preponderance and are more likely epithelioid rather than spindle cell histology.

Biopsy is important not only to diagnose the tumor, but also permit molecular testing to further characterize the lesion and guide therapy. GISTs are intramural and biopsy must be deep enough to make the diagnosis. Although complete surgical resection offers the best option for cure, in children these tumors are very indolent and the recurrence rate is high. Recurrence rates seem to be similar with aggressive resections and wedge resections, favoring a less heroic approach. Involved nodes should also be sampled. Standard chemotherapy and radiotherapy are largely ineffective. The protein kinase inhibitor imatinib has proven effective as adjuvant therapy for adult disease, but not for “wild type” GIST. Additional protein kinase inhibitors such as sunitinib and reforafenib may be used in refractory cases. The tumors in children are typically more indolent than in adults.

[Dayib]

E

[Admin]

think again my dear

[Secundino López Ibarra]

Intraoperative biopsy and with the result direct immediate treatment

[Admin]

think again my dear

[Sharon]

C

[Kawtar surg]

C

[Admin]

correct answer
C Wedge resection

Gastrointestinal stromal tumors (GIST) are rare soft tissue sarcomas thought to arise from the interstitial cells of Cajal. Most develop within the stomach (60%) or small intestine (30%), but may occur anywhere from the esophagus to the rectum. Pediatric GISTs are exceedingly rare with several distinctions from their adult counterparts. Mutations in KIT and platelet derived growth factor receptor alpha (PDGFRA) have been identified in over 90% of adult patients. However, pediatric patients lack these activating mutations in the receptor tyrosine kinase that drive tumor formation in adults. As such, they are referred to as “wild type” GIST. Interestingly, despite the lack of somatic KIT mutations these tumors still have levels of KIT activity similar to the adult mutant GISTs. Pediatric GISTs may be associated with hereditary syndromes such as Carney triad (GIST, pulmonary chondroma and paraganglioma) and neurofibromatosis type 1. In the Carney-Stratakis dyad (GIST and paraganglioma) germline inactivating mutations have been identified in the succinate dehydrogenase (SDH) genes.

Most pediatric cases present between 10 and 18 years of age. The most frequent clinical feature of pediatric GIST is anemia - symptomatic either through acute or subacute bleeding. No palpable tumor, abdominal pain or vomiting are evident in most cases. Unlike the adult tumors they have a female preponderance and are more likely epithelioid rather than spindle cell histology.

Biopsy is important not only to diagnose the tumor, but also permit molecular testing to further characterize the lesion and guide therapy. GISTs are intramural and biopsy must be deep enough to make the diagnosis. Although complete surgical resection offers the best option for cure, in children these tumors are very indolent and the recurrence rate is high. Recurrence rates seem to be similar with aggressive resections and wedge resections, favoring a less heroic approach. Involved nodes should also be sampled. Standard chemotherapy and radiotherapy are largely ineffective. The protein kinase inhibitor imatinib has proven effective as adjuvant therapy for adult disease, but not for “wild type” GIST. Additional protein kinase inhibitors such as sunitinib and reforafenib may be used in refractory cases. The tumors in children are typically more indolent than in adults.

[QATIF]

A

[Admin]

see correct answer in post above yours