Pleuropulmonary Blastoma - Childhood: Diagnosis

Approved by the Cancer.Net Editorial Board, 06/2021

ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. Use the menu to see other pages.

Doctors use many tests to find, or diagnose, a tumor. They also do tests to learn if the tumor has spread to another part of the body from where it started. If this happens, it is called metastasis. For example, imaging tests can show if the tumor has spread. Imaging tests show pictures of the inside of the body. Doctors may also do tests to learn which treatments could work best.

For most types of cancer, a biopsy is the only sure way for the doctor to know if an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.

How PPB is diagnosed

There are many tests used for diagnosing PPB. Not all tests described here will be used for every person. Your child’s doctor may consider these factors when choosing a diagnostic test:

  • The type of cancer suspected

  • Your child’s signs and symptoms

  • Your child’s age and general health

  • The results of earlier medical tests

The diagnosis of PPB depends on an examination under a microscope of material (either cyst material or solid tumor tissue) from inside the chest. In Type I, or cystic, PPB, the cysts appear only slightly abnormal, but very close evaluation shows that the walls of the cysts contain very small collections of cancerous cells. In Types II and III PPB, it is obvious when looking under a microscope that tissue inside the chest is cancerous, but because PPB is so rare, it may be difficult for the doctors to determine exactly what type of tumor it is. In Types II and III PPB, it can spread to the heart, so doctors might also check the great vessels of the heart and the chest cavity as well. Often, doctors will send tissue samples to other experts for help determining the correct diagnosis.

In addition to a physical examination, the following tests may be used to diagnose PPB:

  • Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that a tumor is present, but only a biopsy can make a definite diagnosis. A pathologist then analyzes the sample(s). A pathologist is a doctor who specializes in interpreting laboratory tests and evaluates cells, tissues, and organs to diagnose disease.

  • X-ray. An x-ray is a way to create a picture of the structures inside of the body using a small amount of radiation.

  • Computed tomography (CT or CAT) scan. A CT scan takes pictures of the inside of the body using x-rays taken from different angles. A computer combines these pictures into a detailed, 3-dimensional, or 3-D, image that shows any abnormalities or tumors. A CT scan can be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow. After a chest x-ray shows something abnormal in the lungs, a CT scan is the best method for obtaining more information about PPB.

  • Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed pictures of the body. MRI can also be used to measure the tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow. An MRI is not as good as a CT scan to look inside the chest for PPB, but it is often the best test for looking at other parts of the body to determine if the tumor has spread.

  • Bone scan. A bone scan uses a radioactive tracer to look at the inside of the bones. The amount of radiation in the tracer is too low to be harmful. The tracer is injected into a patient’s vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears lighter to the camera, and areas of injury, such as those caused by a tumor, stand out on the image.

After diagnostic tests are done, your child’s doctor will review the results with you. If the diagnosis is PPB, these results also help the doctor describe the tumor. This is called staging.

The next section in this guide is Stages. It explains the system doctors use to describe the disease. Use the menu to choose a different section to read in this guide.