We describe a case of poorly differentiated gastric neuroendocrine carcinoma presenting as a wandering exophytic mass. CT imaging revealed a 14.5x10.0x8.0 cm, lobulated, solid mass with a multifocal necrotic portion at the right of the peritoneal cavity. It was attached to the antrum of the stomach by a broad stalk, and shown by MR imaging to be well-defined, lobulated and solid, with a multifocal necrotic portion, and at the left of the peritoneal cavity. Isointensity was apparent at T1-weighted imaging, and slightly hyperintensity at T2-weighted imaging, and after gadolinium injection, enhancement was stronger than at precontrast imaging.