Introduction: Myeloid sarcoma or granulocytic sarcoma is a rare extramedullary manifestation of acute myeloid leukaemia. It is a tumour mass consisting of myeloblastic cells or immature myeloid cells and is associated with a poor prognosis. Diagnosing a myeloid sarcoma is challenging due to its non-specific clinical and radiological findings.

Introduction: The incidence of patients with rectal neuroendocrine tumours (RNET) is on an exponential rise. This is due to the increasing awareness and improving knowledge of the disease resulting in earlier detection via colorectal cancer screening programmes. The latest guidelines suggest transanal, endoscopic or surgical treatment depending on the size, nature and stage of the tumour, with non-specific post-treatment surveillance.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the alimentary canal and are postulated to have originated from the interstitial cells of Cajal. We present three patients with an age range from 43 to 63 years old diagnosed with GIST of the gastroesophageal junction (GEJ). All patients were noted to have submucosal lesions through gastroscopy, in which the largest was 5 cm × 7 cm in size. All of them underwent emergent surgery due to various reasons, and the Merendino procedure was performed as the surgery of choice. All of them recovered well and were discharged on days 10–12. The histopathological examination demonstrated a GIST. Merendino procedure can improve patients' digestive functions and nutritional status, leading to a better quality of life after surgery with a reduction in postoperative complications. This case series demonstrated proximal gastrectomy with Merendino procedure reconstruction as a safe, efficient, and feasible approach in treating gastric GISTs at the GEJ.