We report the case of a female patient who had a neuroendocrine tumor in the pancreatic tail. Followup using (68)Ga DOTA-d-Phe(1)-Tyr(3)-octreotide (DOTATOC) positron-emission tomography (PET)/computed tomography (CT) detected a round, well-circumscribed nodular mass that exhibited positive somatostatin receptors. This finding was highly suggestive of an accessory spleen; however, due to the slight elevation of the tumor marker, recurrence of the tumor or lymph node metastasis of the endocrine tumor was considered as well. Ultimately, splenic scintigraphy (SS) confirmed an accessory spleen. This case shows the benefit of splenic scintigraphy in excluding a recurrent neuroendocrine tumor by confirming an accessory spleen.