CT characteristics of lung nodules present at diagnosis of extrapulmonary malignancy in children

The purpose of this study was to evaluate the CT characteristics of lung nodules present at diagnosis of extrapulmonary malignancies in children.

We performed a retrospective analysis of CT images of children seen in our oncology service over a 6-year period. We included all children diagnosed with a non-CNS solid extrapulmonary malignancy or lymphoma who had also undergone chest CT at presentation. Images were reviewed for the presence of lung nodules; if present, the following nodular characteristics were recorded: sidedness, number, distribution, CT attenuation, shape, margins, calcification, and size. When available, pathology results were correlated with the nodules found on CT.

One hundred eleven infants and children (age range, 14 days-17 years 10 months; median age, 11 years 8 months) had lung nodules on CT. The nodules showed a variety of patterns, but the most common findings were bilateral lung nodules (71 of 111 patients), between two and 10 in number (60 patients), peripheral distribution (98 patients), < or = 5 mm (48 patients), oval shape (45 patients), solid attenuation (74 patients), smoothly marginated (91 patients), and noncalcified (107 patients). Twenty-seven patients underwent biopsy. Seventeen biopsies showed benign lesions and nine, malignant lesions; the results for the remaining biopsy were inconclusive. In the subgroup of lung nodules that underwent biopsy, none of the CT characteristics was able to differentiate benignity from malignancy.

Lung nodules in children with extrapulmonary malignancies showed a variety of patterns on CT. In the subgroup of lung nodules that underwent biopsy, none of the nodule features studied on CT reliably differentiated benignity from malignancy.