Diagnostic algorithm of neuroendocrine tumors of the digestive system (GEP-NET) and bronchi

The aim of this study was to characterize current trends in the diagnostic approach to neuroendocrine tumors and to construct a diagnostic algorithm. This study included 59 patients with pathologically confirmed neuroendocrine tumors (NETs). Serum CgA was assessed in 50 of them. All patients had standard spiral CT. Functional imaging was performed using somatostatin receptor scintigraphy (SRS). Histological assessment was performed in each case and consisted of standard HE staining and immunohistochemistry. There were 6 patients with well-differentiated neuroendocrine tumors (NETWDs). The second group consisted of 38 patients with neuroendocrine carcinoma of low malignancy (NECLM). Third group of patients consisted of 11 cases of neuroendocrine carcinoma of high malignancy (NECHM). The fourth and last group consisted of 4 patients with mixed tumor type, i.e.neuroendocrine carcinoma with adenocarcinoma. The locations of the primary lesions were as follows: 9 patients had bronchial/neck tumors, 23 patients bowel tumors, 20 patients pancreatic tumors, and 7 had tumors of unknown origin. Eleven patients had secretory tumors with clinical symptoms. The sensitivity of CT to assess the presence of a primary tumor was 72% and to assess the presence of metastatic disease 67%. The sensitivity of SRS was 69% in primary and secondary disease. Using both modalities, the sensitivity for primary tumor rose to 81% and for metastatic disease to 78%. To improve diagnostic accuracy, CT and SRS should be assessed together High accuracy of SRS was noted in NETWD and NECLM. The key point of patient management are the results of pathology and immunohistochemistry. (author)