Staging is a way of describing where a tumor is located, if or where it has spread, and whether it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the tumor's stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis (chance of recovery). There are different stage descriptions for different types of tumors.

The following criteria help doctors describe PPB:

Type I: Type I PPB generally occurs in children younger than one year and is made up of mostly cysts, with almost no nodules (small, solid tumors). A thin layer of the wall of the cyst may appear cancerous. Type I PPB usually has the best prognosis of the different types. 

Type Ir: Type Ir is made up of cysts that do not contain cancerous cells.

Type II: Type II PPB contains both cysts and cancerous nodules, and occurs most commonly in children around three years old.

Type III: Type III PPB is a solid cancerous tumor, and occurs most often in children around four years old.

Recurrent: Recurrent cancer is cancer that comes back after treatment. If there is a recurrence, the tumor may need to be staged again (called re-staging) using the criteria above.

Sources: Dehner LP: Pleuropulmonary blastoma is THE pulmonary blastoma of childhood. Seminars in Diagnostic Pathology 11:144-51, 1994, and The International PPB Registry.