What is a Solid Tumor?

A tumor is an abnormal clump of cells. When your child has a solid tumor, that means the tumor doesn't contain any liquid or cysts.

Solid tumors can occur in several places. They include:

• Bones
• Muscles
• Organs

Not all tumors are cancer. A tumor that does not have any cancer cells is called benign. A tumor with cancer cells is called malignant.

Solid tumors and blood cancers

Doctors divide cancer into two main types: solid tumor cancers and cancers in the blood. Cancers in the blood are also called hematological cancers. Cancers in the blood don't form tumors.

In hospitals, doctors who treat solid tumors are often in a different department than those who treat blood cancers.

Meet the doctors and specialists at St. Jude who treat solid tumors

Major types of solid tumors

Two major types of solid tumors are sarcomas and carcinomas. Many types of solid tumors, whether a sarcoma or a carcinoma, are often treated with surgery.

1. Sarcomas are tumors in a blood vessel, bone, fat tissue, ligament, lymph vessel, muscle or tendon. There are many types of sarcomas. They include:
   • Ewing sarcoma and osteosarcoma, which are bone cancer sarcomas.
   • Rhabdomyosarcoma, which is a soft tissue sarcoma found in muscles.
2. Carcinomas are tumors that form in epithelial cells. Epithelial cells are found in the skin, glands and the linings of organs. Those organs includes the bladder, ureters and part of the kidneys. 
   • One common carcinoma is adrenocortical carcinoma. This is when a tumor develops in one or both adrenal glands, located above each kidney.

Common pediatric solid tumor cancers

Solid tumors make up about 30% of all cancers in children. The most common type of solid tumor found in children is a brain tumor. After brain tumors, the most common types are:

• Neuroblastoma: a cancer usually found in the belly. This type of cancer occurs in infants and young children.
• Wilms tumor: a cancer found in one or both kidneys. This type of cancer is found in children about 3 to 4 years old.
• Rhabdomyosarcoma: cancer found in skeletal muscle cells. It can occur almost anywhere in the body.
• Retinoblastoma: cancer found in the eye. This cancer occurs in children around age 2.
• Osteosarcoma and Ewing sarcoma, two types of bone cancer. Osteosarcoma most often occurs near the joint of a leg or arm bone of teens. Ewing sarcoma is most common in the hip, middle of the long leg bones, ribs or shoulder blades in young teens.