Published online Aug 10, 2013. doi: 10.5306/wjco.v4.i3.70
Revised: April 23, 2013
Accepted: May 7, 2013
Published online: August 10, 2013
Processing time: 123 Days and 13.2 Hours
Gastrointestinal stromal tumors (GISTs) represent a malignant gastrointestinal tumor of neurofibromatosis type 1 (NF1) Von Recklinghausen disease. In the current case, we report a 27-year-old woman with NF1, who presented with a lower abdominal mass, symptomatic anaemia, and significant weight loss. We employed multiple approaches to assess the tumor behavior, including computed tomography (CT) scan, surgical tumor resection, histological and immunohistochemical analysis and gene sequencing. Additionally, the patient was given Imatinib mesylate (Gleevec) as adjuvant therapy. CT scan delineated a large thick wall cavity lesion connecting to the small bowel segment. Resection of the tumor yielded a mass of 17 cm × 13 cm with achievement of safety margins. The diagnosis was GIST, confirmed by immunohistochemical expression of CD117, CD34, and Bcl-2. Sequencing revealed no mutations in either KIT or platelet-derived growth factor receptor-alpha, genes which are mutated in over 85% of sporadic GIST cases. Further, there was no evidence of recurrence, metastasis or metachronous GIST for over three years in our patient. From our analyses, we believe selective genotyping is advisable for high risk patients to predict potential tumor behavior.
Core tip: There are several differences between gastrointestinal stromal tumors (GISTs) in a neurofibromatosis type 1 (NF1) patient and sporadic GISTs with regard to the tumor site, tumor behavior, targeted therapeutic approach, survival, prognosis, and recurrence based on genomic mutations. Wild type GISTs, those that do not have mutations in KIT or platelet-derived growth factor receptor-alpha (PDGFR-α), are typically resistant to imatanib therapy. Mutational analysis is critical in predicting tumor behavior and might individualize targeted therapy. We show that sequencing for KIT and PDGFR-α provide a useful tool in predicting tumor behavior of GIST in a NF1 patient.