Imaging description

A previously healthy 10-year-old girl presented with shortness of breath for 10 days. A frontal chest radiograph (Fig. 22.1a) demonstrated complete opacification of the left hemithorax with cardiomediastinal shift to the right, raising concerns of a left-sided mass versus large effusion. She was afebrile. A contrast-enhanced CT scan (Fig. 22.1b) revealed low-density material, thought to be fluid, filling the left pleural space; the left lung was completely atelectatic. A subtle finding on the CT was lytic expansion of two lower left ribs (Fig. 22.1b). Concern was raised for an underlying neoplasm such as Ewing’s sarcoma or leukemia/lymphoma and a chest MR was obtained (Fig. 22.1c). This demonstrated bright T2-weighted signal in the pleura, mediastinum, lower ribs, and adjacent chest wall with large complex organizing pleural fluid. In addition, multiple splenic cysts were noted. No discrete mass and no abnormal enhancement was seen postcontrast. The diagnosis of lymphatic abnormality, likely lymphangiomatosis, with pleural, bone, and splenic involvement was suggested by the interpreting radiologist. On ultrasound (US), the fluid was also shown to be complex and septated consistent with proteinaceous fluid (Fig. 22.1d). The pleural fluid was drained and found to be chylous; pleural biopsy showed dilated lymphatics without definite proliferative findings.