Radiological and pathological features of intrapulmonary lymph nodes

Abstract

Background:The widespread use of CTs has increased the ability to detect small pulmonary nodules. The differentiation of intrapulmonary lymph nodes (IPLNs) from other small pulmonary nodules (cancer, tuberculosis and mycosis, etc) on CT images is clinically very important, although it is often difficult. Aims:The purpose of this study was to find out clinical features of IPLNs. Methods:Eight patients (male 6 / female 2, age 52-69) who underwent thoracic surgery for pulmonary nodules, were pathologically diagnosed with IPLNs. We retrospectively evaluated the clinical backgrounds, thin-slice CT findings and pathological features of IPLNs. Results:Two patients had newly-diagnosed lung cancer and five patients had known malignant cancer other than lung. Six patients had smoking history. The number of nodules ranged 1 to 8. The size was equal to, or 10 mm, with median diameter of 7.74mm. Each border was clearly demarcated. All nodules were placed in the peripheral lung and the median distance away from pleura was 2.95mm. The nodules in seven patients (88%) had thin linear attachments extending to pleura and were in contact with a periperal pulmonary vein on CT. The nodules in six patients (75%) were located in the lower lobe. The pathological finding showed anthracosis and no silicosis in all cases. Conclusions:The IPLNs had a thin linear attachments extendings to pleura and were separated from pleura by a distance of a few millimeters. All IPLNs had anthracosis and could be related to passive smoking in patients without smoking history. Considering clinical features, careful discrimination of IPLNs from other pulmonary nodules may avoid both unnesessary surgeries and follow-up examinations.