Pleuropulmonary blastoma (PPB) is a rare type of childhood lung tumor that begins in the chest either in the lung tissue (pulmonary) or in the tissue that covers the lungs and the inside of the pleura, also called the chest cavity. A tumor begins when normal cells change and grow uncontrollably, forming a mass called a tumor. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can spread to other parts of the body. A benign tumor means the tumor will not spread.
There are four types of PPB:
- Type I is made up of air pockets called cysts with early evidence that it is cancerous. However, it is difficult to find and diagnose in this early form. It occurs in very young children, who on average are 10 months old, and has a better chance of being successfully treated than Types II and III, described below.
- Type Ir is similar to Type I, but it does not have cancerous cells. The “r” stands for regressing.
- Types II and III generally occur in children ages three to four. Types II and III are cancerous tumors and require intensive chemotherapy.
Many patients with PPB have a mutation of the DICER1 RNase-IIIb gene. More details on the different types of PPB are explained in other sections, including more information about genetic factors in Risk Factors.
Looking for More of an Overview?
If you would like additional introductory information, explore this related item. Please note this link takes you to another section on Cancer.Net:
- Cancer.Net Patient Education Video: View a short video led by an ASCO expert in childhood cancer that provides basic information and areas of research.