Complete pathological response to Imatinib mesylate in an extraintestinal gastrointestinal stromal tumor

Abstract

INTRODUCTIONGastrointestinal stromal tumors (GIST) are the most frequent mesenchymal tumors of the digestive tract. Extraintestinal locations (EGIST) have been described showing similar pattern of immunohistochemical markers than GIST. Inhibitors of tyrosine kinases such as Imatinib or Sunitinib are the mainstay treatment in the management of advanced or metastatic GIST. Complete pathological response to these agents is an extremely rare event, especially in the case of EGIST due to its more aggressive behavior reported.PRESENTATION OF CASEHere we describe the case of a 61 years old woman, with an advanced GIST, who was operated after 10 months of Imatinib mesylate. The biopsy demonstrated the extra intestinal location of the tumor and a complete pathological response was confirmed.DISCUSSIONComplete pathological response to Imatinib is a rare event. To our knowledge, this is the first report of complete response in an EGIST. New clinical, radiological and metabolic criteria of tumoral response to neoadjuvant treatment are revised.CONCLUSIONEGIST complete pathological response to Imatinib can be achieved. However, recommendation of systematic neoadjuvant therapy with Imatinib remains investigational and more studies are warranted in the future.

Extragastrointestinal Stromal Tumor: A Differential Diagnosis of Compressive Upper Abdominal Tumor

“…Once the diagnosis is established, it is necessary to stage the tumor for better management [ 7 ]. The study patient was staged as T4N0M0 and nonresectable.…”

Extra-gastrointestinal stromal tumor presenting as a huge peritoneal mass and mimicking as mesothelioma – A case report

“…The treatment of choice for the E-GIST is the enbloc resection of tumor with macroscopically negative margin followed by adjuvant imatinib as most of the patients fall into high-risk category for recurrence [ 4 ]. In borderline resectable primary tumors, preoperative imatinib is a possible option but there are no randomized trials assessing the benefit of neoadjuvant treatment [ 19 ]. Tumor location is also one prognostic factor for GIST, and it was considered that E-GISTs are more aggressive than gastric GISTs [ 11 ].…”

Extragastrointestinal stromal tumor of the inferior vena cava: a case report

“…In our case, adjuvant therapy was not administered because there was no evidence of metastases and recurrences and the tumor was originating from the media of the vessel wall. Although distinction between GIST and LMS is important, GIST might be effectively treated with tyrosine kinase inhibitors, such as imatinib mesylate [ 17 , 18 ]. There is the possibility that GIST occurred in the present case, which was initially reported as LMS of the IVC because those were histologically classified together as LMS owing to their similarities as determined via light microscopy.…”