NETs (neuroendocrine tumors) constitute a heterogeneous group of epithelial-type neoplasms with a predominantly neuroendocrine differentiation. Although the most common locations are the pancreas, digestive tract, and lung, this type of neoplasm can arise in virtually any organ in the body. They are rare tumors with a wide variety of clinical presentations. Symptomatic tumors are more frequent in younger patients and present at more advanced pathological stages. We present the case of a 42-year-old male with idiopathic splenomegaly and bicytopenia (anaemia and thrombocytopenia) under study by haematology department who was admitted due to an episode of melena and hemoglobin of 4.5 mg/dl. Isolated gastric varices (IGV1) with red spots were confirmed at gastroscopy and endoscopic variceal obturation using cyanoacrylate was performed in two sessions. An endoscopic ultrasonography was performed, showing thrombosis of the splenic vein extending towards the splenoportal confluence with anechoic serpiginous structures outside and inside the gastric wall suggestive of collateral circulation with gastric varices (GV). An increase in portal caliber was observed, with no signs of liver cirrhosis. Computed tomography confirms the findings. Two months/week/days later he was readmitted with rebleeding signs after starting anticoagulant treatment, so it was decided to perform a splenectomy due to failure of the endoscopic treatment. Histology revealed infiltration of the spleen by a well-differentiated neuroendocrine tumor (NET). Gallium PET/CT and Octreotid scan showed uptake in the body and tail of the pancreas with positivity for somatostatin receptors previously undetected by other means. Finally, treatment was completed with distal pancreatectomy and splenoportal axis trombectomy with vascular esplenic resection and the patient was discharged from hospital.