Synchronous gastric GIST and adenocarcinoma: case report and literature review

Background - Gastrointestinal stromal tumors (GISTs) are an uncommon mesenchymal neoplasm affecting the GI tract. The synchronous occurrence of mesenchymal tumors and other primary gastrointestinal malignancies have been rarely reported in the literature. Case report - A 61 year-old female patient came to our department complaining of diffuse abdominal pain, which had begun 2 years ago. At physical examination a mass with approximately 10 cm, located in the upper abdomen, was palpable. A CT scan demonstrated a mass in contact with the greater gastric curvature without lymphnodal enlargement. At endoscopy, no lesions were seen in the greater curvature, but a 2,0 cm mucosal lesion was visualized in the upper portion of the lesser curvature. The biopsy of the lesion in the lesser curvature was positive for adenocarcinoma. An endoscopic ultrasound was performed and demonstrated that the lesion in the lesser curvature was restricted to the gastric muscular layer and the mass in the greater curvature was originated from the gastric fourth ultrasonographic layer (muscular). The patient was submitted to a total gastrectomy with D2 lymphadenectomy and a Y of Roux esophago-jejunal anastomosis. The pathological exam demonstrated that the lesion in the lesser curvature was a microtubular adenocarcinoma restricted to the muscular layer. The lesion in the greater curvature was a high grade GIST. The final TNM stage was T2N1M0. The patient recovery was uneventful being discharged from the hospital after 11 days. Conclusion - The synchronous occurrence of GISTs and other gastrointestinal malignanies is more common than has been considered. Although the synchronous occurrence of GIST and other abdominal malignancies seems to be just a coincidence, the development of these tumors may involve common carcinogenic agents.