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

OBJECTIVE: The purpose of this study was to evaluate the CT characteristics of lung nodules present at diagnosis of extrapulmonary malignancies in children. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Pulmonary Langerhans cell histiocytosis: a variable disease in childhood.

BACKGROUND: Pulmonary Langerhans cell histiocytosis (PLCH) is rare in childhood but occurs most commonly in children with multisystem (MS) LCH. In adults, by contrast, the lung is the most common and usually the sole organ affected. This retrospective study describes the clinical manifestation, course, and outcome of PLCH in children consecutively diagnosed at two Canadian institutions. PROCEDURE: The medical records of children (<18 years of age) consecutively diagnosed with LCH at the two institutions, were examined to ascertain the demographic details, pathological diagnosis, and organs involved. Further clinical details including, the clinical manifestation, details of therapy, course of lung disease, and clinical outcome were extracted for patients with PLCH. Initial and follow-up lung radiographs and CT scans were re-reviewed. RESULTS: Of the 178 patients with LCH, 40 (22.5%) presented with MS disease. Thirteen (7.3%) had PLCH, seven at initial diagnosis, and six at the time of disease progression. The median age was 10.1 months and mean was 11.9 months at diagnosis of PLCH. Lung involvement was always in the context of MS LCH, and half of the patients had no respiratory symptoms. Disease-free survival was around 70%, with a mean follow-up duration of 7 years. Of the four patients who died, three had other risk-organ involvement. Five of the nine surviving patients have had complete radiological resolution of PLCH. CONCLUSION: PLCH is seen in less than 10% of childhood LCH, but more than 30% of MS LCH. About half of children with PLCH may be asymptomatic, and the prognosis appears to depend on the presence or absence of other risk-organ involvement. The MS PLCH found in children appears to be a different disease from the single system (SS) PLCH seen in adults.