Although many types of pancreatic tumors exist, pancreatic solid serous cystadenoma stand as the most rare. Despite advances in medical imaging, definitive diagnosis remains complex. Here, we report a case of a 63-year-old man with a suspicious lesion of the pancreas discovered during a positron emission tomography–computed tomography. Despite an echo-endoscopy being performed, no biopsies were contributive. The magnetic resonance imaging did highlight another lesion in the liver. Due to the suspicion of a neuroendocrine tumor of the pancreas with liver metastases, a cephalic duodenopancreatectomy with partial hepatectomy was performed. During the procedure, another hepatic lesion was resected. The final histological diagnosis was a serous solid adenoma of the pancreas associated with a cholangiocarcinoma. During the follow-up, the patient presented a massive metastatic hepatic relapse even after the administration of a palliative chemotherapy.