ABSTRACT
Objective Typical carcinoma(TC), atypical carcinoma(AC) and large cellul neuroendocrine carcinoma (LC-NEC) are rare pulmonary neuroendocrine tumor (PNET) possessing different pathological features , biological behaviors and clinical prognosis .The paper aimed to investigate the characteristic CT findings of rare pulmonary neuroendocrine carcinoma in comparison with pathological diagnosis . Methods A retrospective analysis was conducted on clinical data , CT findings and pathological results of 22 patients admitted in the Affiliated Hospital of Nanjing University of TCM from 2010 to 2016, followed by statistical analysis . Results Among the 22 cases, there were 9 females and 13 males, 12 cases of central type and 10 cases of peripheral type , 7 cases with calcifi-cations, 10 cases with focal necrosis , 6 cases with combined bronchial obstruction sign , 5 cases with lymph node metastasis , and 1 case with distant metastasis.TC was presented with younger onset age , while AC and LCNEC with older onset age (P=0.003).TC ten-ded to be central type (P=0.044), mainly charaterized by bronchial lumen nodules (P=0.005) with smooth edges (P=0.000) and often accompanied with obstructive pneumonia and atelectasis ( P=0.019) without pleural involvement .AC mostly belonged to central type , charaterized by multilobulated soft tissue masses , elongated or"iceberg"in typical ones , with rare obstruction signs and no obvi-ous pleural involvement.LCNEC was mostly peripheral, with lobulated lesion margin (P=0.000), no obvious obstruction signs, and frequent pleura involvement ( P=0.000 ) . Conclusion Rare pulmonary neuroendocrine tumors have certain characteristic clinical features and CT findings .TC has the youngest onset age , mainly characterized by bronchial lumen nodules with smooth edges and often accompanied with obstruction signs , while LCNEC has the oldest on-set age and tends to be peripheral , mostly without obstruction signs and with frequent pleura involvement .