Neuroendocrine Tumor of Unknown Primary Accompanied with Stomach Adenocarcinoma

A 67 year old male at a regular checkup underwent esophagogastroduodenoscopy. On performing esophagogastroduodenoscopy, a lesion about 1.2 cm depressed was noted at the gastric angle. The pathology of the biopsy specimen revealed a well-differentiated adenocarcinoma. On performing an abdominal computed tomography (CT) scan & positron emission tomography-computed tomography (PET-CT) scan, no definite evidence of gastric wall thickening or mass lesion was found. However, lymph node enlargement was found in the left gastric and prepancreatic spaces. This patient underwent laparoscopic assisted distal gastrectomy and D2 lymph node dissection. On final examination, it was found out that the tumor had invaded the mucosal layer. The lymph node was a metastasized large cell neuroendocrine carcinoma with an unknown primary site. The patient refused chemotherapy. He opted to undergo a close follow-up. At the postoperative month 27, he had a focal hypermetabolic lesion in the left lobe of the liver that suggested metastasis on PET-CT scan. He refused to undergo an operation. He underwent a radiofrequency ablation.