Grade 3, well-differentiated, gastric
neuroendocrine tumors (NET G3) are extremely rare. Herein, we report the case of a 64-year-old man with a grade 3
neuroendocrine tumor of the stomach who experienced intra-abdominal
bleeding during the course of drug treatment. The patient was referred to our hospital for examination of a gastric
tumor that was initially diagnosed by a local medical doctor. Esophagogastroduodenoscopy revealed an elevated lesion with a central
ulcer in the upper body of the stomach, and biopsy specimens confirmed the pathological diagnosis of NET G3. Abdominal contrast-enhanced computed tomography (CT) showed a 25-cm, well-defined mass lesion showing heterogeneous enhancement in the liver. A clinical diagnosis of NET G3 with multiple liver
metastases was given, after which
everolimus was administered in combination with a
somatostatin analogue. However, the patient developed sudden-onset epigastric
abdominal pain and general
fatigue 2 months later, and emergency abdominal contrast-enhanced CT confirmed the presence of intra-abdominal
hemorrhage. Following
blood transfusion, the patient's symptoms and general condition improved. Although the patient was treated with
streptozocin, abdominal CT indicated progression of the liver
metastases. Unfortunately, despite receiving best supportive care, the patient died 8 months after the initial of the treatment. To the best of our knowledge, this is the first case of a patient who developed spontaneous
hemoperitoneum during drug treatment for a NET G3 to be reported in the English literature. It is essential that additional data be obtained to determine the optimal treatment for this disease.