J Gastric Cancer.  2011 Dec;11(4):234-238.

Neuroendocrine Tumor of Unknown Primary Accompanied with Stomach Adenocarcinoma

• Kim HY
• Choi SI
• Kim YH

Abstract

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.

Keyword

Gastric cancer; Neuroendocrine tumors; Neoplasms, unknown primary

MeSH Terms

Adenocarcinoma
Biopsy
Carcinoma, Neuroendocrine
Electrons
Endoscopy, Digestive System
Follow-Up Studies
Gastrectomy
Humans
Liver
Lymph Node Excision
Lymph Nodes
Male
Neoplasm Metastasis
Neoplasms, Unknown Primary
Neuroendocrine Tumors
Stomach
Stomach Neoplasms

Figure

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  Fig. 1 Preoperative abdominal computerd tomography scan (A) and positron emission tomography-computerd tomography (B).

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  Fig. 2 The resected specimen showed two early gastric cancers. One tumor was 1.5×1.0 cm, early gastric cancer (EGC) type III lesion at the lower body of the stomach. The other was a 1.2×1.0 cm, EGC type IIc lesion at the angle of the stomach.

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  Fig. 3 Lymph node sections showed that the tumor tissue consisted of neoplastic pleomorphic large cells with palisading, trabecula and sinusoid pattern (hematoxylin-eosin stain, original magnification, ×12.5).

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  Fig. 4 The tumor cells of neuroendocrine carcinoma showed positive stains for CD56, chromogranin and synaptophysin on immunohistochemical stains (CD56, original magnification, ×100).

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  Fig. 5 Postoperative liver magnetic resonance imaging (MRI) & positron emission tomography-computerd tomography (PET-CT) scan. At postoperative month 27, the patient had a focal hypermetabolic lesion in the left lobe of the liver that suggested metastasis on PET-CT (B, C). The tumor was 2.3 cm and oval shaped on MRI over the liver (A).

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