Pleuropulmonary blastoma (PPB) is the most common primary malignancy of the lung parenchym in children. PPB has a spectrum of gross and microscopic morphology, from low-grade cystic lesions to high-grade solid forms.
PPB is classified by gross features as:
- type I (cystic),
- type II (solid and cystic), and
- type III (solid).
PPB is distinguished from adult-type pulmonary blastoma by the absence of malignant epithelial components. The clinical suspicion of malignancy at the time of surgery is often low, as these lesions mimic congenital pulmonary airway malformation by both diagnostic imaging and gross examination.