CT differential diagnosis of primary nodular mucinous adenocarcinoma and tuberculoma: Evaluation of 61 solitary solid nodules

Abstract

Objective: To discriminate pulmonary nodular mucinous adenocarcinoma(PNMA) from tuberculoma with dynamic CT. Methods: In this study, 61 pathologically confirmed lesions (38 PNMAs and 23 tuberculomas) were enrolled. The mean CT attenuation of lesion of the plain, the enhanced scan, and the enhanced values (CT attenuation of lesion of enhanced scan minus that of plain scan) were tested with an independent t-test pair-wisely. The logistic regressions and receiver operating characteristic curve analyses were performed to test the differential diagnosis values. The presence of satellite lesions was determined with the chi-square test. Results: The mean CT attenuation of tuberculoma of the plain scan was significantly higher than that of PNMA [(35.15±16.00) HU vs (24.00±12.67) HU, t=3.02, P< 0.001].The enhancement value of tuberculoma after enhancement was significantly lower than that of PNMA [(13.44±13.40) HU vs (22.52±14.00) HU, t=-2.49, P=0.02)]. The optimum CT attenuation of plain scan and the enhanced value for differential diagnosis were 28.80 and 14.25 HU[Area under the curve(AUC) 0.721; 95%CI: 0.58-0.86; and AUC 0.697; 95%CI: 0.59-0.84], with sensitivity and specificity of 78.3%, 63.8% and 71.1%, 69.6%, respectively. The satellite lesions were more often observed in the tuberculoma group (χ2=17.51, P< 0.001). Conclusions: The CT attenuation of the plain scan, the enhanced value after enhancement, and the presence of satellite lesions are useful indexes for discriminating PNMA from tuberculoma.