Primary pulmonary neoplasms are uncommon in children. One such tumor, pleuropulmonary blastoma (PPB), is very rare, highly aggressive and malignant, and originates from either the lungs or pleura. It contains both mesenchymal and benign epithelial elements that resemble fetal lung, and occurs mainly in children aged less than five. The clinal symptoms often suggest upper respiratory tract infection or pneumothorax, but ultrasonography and chest CT scans depict both a large mass occupying an almost entire hemithorax, and a simple lung cyst. Contrast-enhanced CT demonstrates hetergeneous attenuation and a whorled appearance.