Childhood Cancer

Childhood Cancer

Diagnosis

Many tests are necessary to confirm a diagnosis of neuroblastoma because symptoms of this disease can mimic other illnesses, including other cancers. A pediatric oncologist will perform a thorough physical examination and order a complete blood count (CBC). The following tests should also be done:

•  Bone is assessed by a meta-iodobenzylguanidine (mIBG) scan (performed in the nuclear medicine department) and, if the results of the mIBG scan are negative, by a technetium 99 scan.

•  Enlarged lymph nodes are examined and biopsied. Lymph nodes that cannot be felt on exam should be assessed by a magnetic resonance imaging (MRI) scan with three-dimensional (3D) measurements.

•  The abdomen (including liver) and pelvis are best evaluated with an MRI, but a computerized tomography (CT) scan with oral contrast can be used to distinguish tumor from loops of intestines.

•  Chest x-rays are done from the front and side. CT scans and/or MRI scans are necessary if the chest x-ray shows a tumor or if an abdominal tumor extends into the chest.

To minimize unnecessary radiation, MRI scans are often done instead of CT scans. For more information on these procedures, see Chapter 10, Coping with Procedures.

Little alarm bells started going off when the radiologist had the technician scan Cam’s abdomen twice. She wanted to get a good look at his liver and all the way to the bottom of his kidneys. A few hours later, the oncologist, psychologist, and nurse clinician all showed up and my stomach sank.

Blood and urine tests, biopsies, and evaluation of many tumor cell characteristics also help a pediatric oncologist make or confirm a neuroblastoma diagnosis. Over 90 percent of neuroblastomas secrete hormones called catecholamines. When catecholamines break down, they produce VMA and HVA, which are found in the urine. A 24-hour urine collection or a single urine sample will be tested for VMA and HVA levels. This test is valuable for making the initial diagnosis and for following the child’s response to treatment.

At the age of 19 months, Justina lost all her motor skills. At first she was clumsy and staggering, but it progressed very rapidly (over a period of 4 days) to a point where she was not able to pull herself up or even sit. Her eyes would bounce, roll back, and circle. She was scared, since she had no concept of where her body was in space. She always felt as if she was falling. Justina was misdiagnosed for 4 months until we finally learned she had neuroblastoma.

To make a diagnosis, the pediatric oncologist needs tumor tissue obtained from a biopsy or surgical removal of tumor (see Chapter 14, Surgery). Every child with suspected neuroblastoma will also have a bone marrow aspiration and bone biopsy done on each hip. These procedures are described in Chapter 10, Coping with Procedures. A pathologist will study the tumor sample, the bone marrow biopsy, and the bone marrow aspirate (liquid part of the bone marrow), and these materials will then be tested for a variety of biologic and genetic factors.

The local hospital did a chest and abdominal CT before they sent him to the children’s hospital. The pediatrician said it was cancer. He said, “We think it’s neuroblastoma but you need a biopsy.” We got a definite diagnosis at the children’s hospital—solid mass 20 centimeters high! It didn’t cross the midline. They speculated he’d had it since he was born.