EXTRAGASTROINTESTINAL STROMAL TUMOR PRESENTING AS A LARGE UPPER SIDE ABDOMINAL TUMOR TWO CASE REPORTS

Man, 46 years old was admitted presenting abdominal pain for 6 months of increasing intensity, loss of weight over8Kg, difficultytoeatandperceptionofalargertumor intra abdominal. He had history of neurifibromatosis with typical skin pigmentation. The CT scan showed solid 20 cm tumor, placed in retroperitoneum between the posterior gastric wall and the tail of pâncreas, without adenopathies. No preoperative biopsy was achieved. The laparotomy was proceeded em block R0 ressection of the tumor, body and tail of pâncreas, spleen and linfonodes. Postoperative the paciente presented had a leakage of pancreas resolved with non-surgical approach. Chemotherapy was permormed with Imatinib Masylate. Woman, 83 years old was admitted for abdominal pain with back irradiation for a year, associated with nausea, vomit and loss of weight of 10 Kg, A CT scan showed a 30cm tumor located in the gastrocolic ligament involving the tail of pâncreas, without adenopathies. Preoperative transgrastric biospy endoscopic-guided showed a gastrointestinal stromal tumor. I was proceeded neoadjuvant chemotherapy with imatinib mesylate for 11 months achieving downstaging and release of the pancreas. Was proceeded surgical ressection R0 of the tumor, without postoperative complications or adjuvante therapy. Although the GISTs represent less than 1% of all cancers, they are the most common mesenchymal neoplasms of the gastrointestinal tract. GIST arises from the gastrointestinal pacemaker cells (Cajal Cells). Althought EGIST is identical in histological and immunohistochemical features with GISTs, they display no connection to the gut wall, representing 10% of the GISTs. Two immunohostochemical markers are considered to be the most sensitive and specific: KIT and DOG-1. Inhibitors of KIT and PDGFRa are options for a neoadjuvant or adjvant treatment, but the surgery is the only treatment leading to a potential cure. Regarding Immunohistochemestry, both of our patients showed the same scenary. The patologial analyses of the case one tumor showed central necrosis with is a criteria of worse prognosis. We reported a 2 rare presentations of EGIST, one neurofibromatosis type 1 related and the other was undergone a neoadjuvant therapy with an excellent response. Altough its not frequent KIT mutation in NF1, they have a good response to imatinib. This may be significant to strenghen the relationship between the presence of the mutation and the use of imatinib therapy

Publication History

Article published online:
23 October 2019