ON THIS PAGE: You will find out more about the factors that increase the chance of developing this type of tumor. To see other pages, use the menu.
A risk factor is anything that increases a person’s chance of developing a tumor. Although risk factors often influence the development of a tumor, most do not directly cause a tumor. Some people with several risk factors never develop a tumor, while others with no known risk factors do.
The cause of PPB is not known. Most often, it develops randomly. For most children with PPB, there may have been no personal or family history of the disease before the PPB occurred; in other words, there was no reason to suspect that the child would develop PPB. Most family members of children with PPB are healthy. The following factors may raise a person’s risk of developing PPB.
Cysts. Early stages of PPB appear as cysts. However, most children with lung cysts do not have PPB.
Family history/genetics. About 2 out of 3 of patients with PPB have a genetic mutation of the DICER1 RNase-IIIb gene, called a germ line mutation. About 80% of patients inherited this gene mutation from a parent.
The DICER1 syndrome is also associated with other cancers such as cystic nephroma, cervical rhabdomyosarcoma, nasal chondromesenchymal hamartoma, ovarian stromal tumors, nodular thyroid hyperplasia, ciliary body medulloepithelioma, and pineoblastoma.
For screening information for PPB and other cancers related to DICER1, see the Latest Research  section of this guide.
The next section in this guide is Symptoms and Signs.  It explains what body changes or medical problems this disease can cause. Or, use the menu to choose another section to continue reading this guide.