CT Findings Of Pulmonary Large Cell Neuroendocrine Carcinoma And Differential Diagnosis With Small Cell Lung Carcinoma

Objective: To analyze the multi-slice spiral CT(MSCT)features of pulmonary large cell neuroendocrine carcinoma(PLCNEC)and to discuss the differentiation of PLCNEC with lung small cell carcinoma(SCLC).Materials and Methods: 30 patients with PLCNEC who were confirmed pathologically to the Shantou central hospital(21cases)and the first affiliated hospital of Shantou university medical college(9 cases)between 2012-2018 were collected,and further contrasted with the findings of34 patients with SCLC who were confirmed pathologically to the shantou central hospital.The clinical and imaging data of PLCNEC group and SCLC group were were collected and summarized.Measurement data with normal distribution were presented as χ±s.Comparison between groups was evaluated with an independent sample t test.and count data were analyzed using the chi-square test.Results: The CT imaging features of PLCNEC were: upper lobe of double lung 80%(24/30),large volume(> 4cm 70%,21/30),clear boundary(21/30,70%),superficial lobulation(26/30,86%),uneven density of plain scan and enhanced scan(73%,22/30).100%,30/30),enhanced scan showed mild to moderate enhancement(90%,19/21),common necrosis(100%,21/21),and multiple or diffuse necrosis(80%,17/21).Hilar and mediastinal lymph node enlargement(60%,18/30)were often associated with necrosis(77%,14/18).The less frequent manifestations of PLCNEC were: spicule sign(13%,4/30),cavity(6%,2/30),atelectasis(26%,8/30),and air bronchi(3%,1/30).The rate of PLCNEC distributed along the bronchovascular bundle,invasion of pulmonary hilar vessels 、heart and mediastinum,lymph nodes enlarged and blended each other were respectively lower than SCLC(20% vs 58%,40% vs 67%,60% vs 94%,11% vs84%,χ2=9.959,15.26,10.85,25.38,P <0.01).Conclusion: PLCNEC have certain imaging features.The higher rate of tumor distributed along the bronchovascular bundle,invasion of pulmonary hilar vessels or mediastinum,lymph nodes enlarged and blended each other are important characteristics for diagnosis and differentiating SCLC from PLCNEC.