Purpose: The purpose of the study is to investigate the computed tomographic characteristic and clinical findings of gastric neuroendocrine carcinoma (G-NEC) to increase awareness of this disease.
Methods: Twenty-two patients with a diagnosis of G-NEC were identified through the PACS of our hospital from August 2010 to November 2014. The clinical data, computed tomography (CT) features, and pathology records were analyzed.
Results: Among the 22 patients, 21 were male (95.45%), and 1 was female (4.55%). The mean age was 63.5 years old. Positive rates of neuroendocrine markers were 77.28% for chromogranin A staining, 86.36% for synaptophysin staining. All cases were single lesions including 16 (72.73%) in the gastric fundus, 3 (13.64%) in the gastric body and 1 (4.55%) in the gastric angle. Additionally 2 (9.09%) were found in the gastric antrum. Gastric wall was local thickening in 15 cases, and mass formation in 7 cases, with the stenosis and deformation of the adjacent gastric cavity. The long-axis diameter of the lesions ranged from 1.2 to7.4 cm (mean diameter, 2.47 cm), and the long-axis diameter was <2 cm in 12 case, 2-7.4 cm in 10 cases. The radiodensity values of the lesions were homogeneous density in 15 cases ranging from 22 to 47 HU (mean 34 HU). An ulcer with an irregular base and slightly raised borders located in the stomach was seen in 19 cases. The CT images showed homogeneous enhancement in 15 cases and heterogeneous enhancement in 7 cases. Obvious enhancement was seen in two cases, moderate enhancement was seen in sixteen cases, and mildly enhancement was seen in four cases. The peak value occurred in the arterial phase in 5 cases and the peak value was seen in 17 cases in the portal phase. Eleven lesions invaded the gastric serosa, and lymphatic metastasis was observed in 21 cases, 8 of which were combined with liver metastasis. CT images revealed 2 cases of the liver metastasis had obvious enhancement.
Conclusion: The CT features regarding location, incidence rates of ulcer and enhancement pattern described in our findings are common in all malignant gastric tumors. Therefore, the diagnosis of G-NEC must be confirmed with pathological test.
Keywords: Diagnosis; Neuroendocrine carcinoma; Tomography computed.