Our goals:

1. To properly diagnose your child’s condition.
2. To help you and your family understand the condition, prognosis, and treatment options.
3. To treat your child with the most up-to-date protocols to provide the best possible outcome and avoid long-term problems.
4. To follow your child long-term to monitor for any recurrence or late effects.

The diagnosis of musculoskeletal tumor or infection initially sounds devastating for patients and families. However, most tumors in children are benign (not cancer) and most infections are curable. Our team will help you understand the unique condition of your child and the best treatment plan for him or her.

The Team

Depending on the diagnosis, your child’s team may include some or all of the following group of specialists: orthopaedic surgeons, radiologists, pathologists, general surgeons, hematologists, oncologists, infectious disease specialists, social workers, psychiatrists and physical therapists. We all work together to diagnose and treat your child’s tumor or infection efficiently and correctly to get the best outcome possible.

MUSCULOSKELETAL TUMORS

The following is for informational purposes only—it is very general and describes the most common manifestations and treatment options for the pediatric musculoskeletal tumors that we see most frequently at Rady Children’s Hospital.

It is important to understand that every case is different and frequently individual cases do not follow the “textbook”. Your doctor will discuss the specifics of your case and the best treatment for your child. Surgical biopsy combined with the radiologic evaluation and clinical exam is the best way to confirm a diagnosis. Many of these lesions are difficult to differentiate without a biopsy.

General Tumor Information

For most bone tumors, the cause is unknown. There are a few that have a known genetic basis (see fibrous dysplasia, ewing’s sarcoma, osteosarcoma). A tumor is created when cells divide in an uncontrolled fashion. A growing tumor may replace healthy tissue with abnormal tissue. This process may cause your child to have pain in the area. If the tumor is aggressive, it can destroy enough bone to weaken it. This can lead to a fracture even with only minor trauma. On x-ray the tumor may appear as a “hole” in the bone.

Most bone tumors in children are benign. Some common types of benign tumors are: unicameral bone cyst (UBC), aneursmal bone cyst (ABC), eosinophilic granuloma (EG), enchondroma, osteochondroma, chondroblastoma, osteiod osteoma, non-ossifying fibroma (NOF) and fibrous dysplasia (FD). Occasionally, bone infections, stress fractures, and other non-tumor conditions can closely resemble tumors.

Some tumors are malignant (cancer). Although they are rare, malignant bone tumors such as osteosarcoma or Ewing’s sarcoma can occur in children. Malignant tumors can spread cancer cells throughout the body (metastasize). This happens via the blood or lymphatic system. The treatment of these tumors may require extensive surgery, chemotherapy or radiation therapy. Your child will be managed by multiple members of the team. Rady Children’s Hospital coordinates with UCSD, St. Jude’s Children’s Research Hospital, and William Bowman, MD—an adult orthopedic oncologist to give the newest and best treatment for malignant musculoskeletal tumors.

Symptoms of a Tumor

• Pain (often described as dull and achy) that may occur mostly at night
• A palpable mass (a lump) somewhere on your body
• Bone fracture with minimal trauma
• Fevers or night sweats
• Loss of appetite/weight loss

Many patients will have no symptoms at all and their tumor will be discovered incidentally when an x-ray is taken for a different injury such as a broken arm. These symptoms are also not specific for a tumor and non-tumor conditions can also present with similar findings.

BENIGN PEDIATRIC MUSCULOSKELETAL TUMORS

Unicameral Bone Cyst (UBC)

• A benign cyst in the bone that is filled with clear/yellow fluid.
• Commonly seen in children and adolescents they typically resolve before adulthood.
• May occur in any bone but most commonly located in proximal humerus and proximal femur.
• Usually asymptomatic until they cause a fracture (acute pain).
• X-ray findings: lytic lesion that is usually central and symmetric
• MRI findings: fluid filled cavity
• UBC’s weaken the bone by thinning the cortex and filling the canal with fluid
• Treatment options:
  • If presents with a fracture, the fracture is managed first and allowed to heal before the cyst is treated.
  • Aspiration and injection with methylprednisolone, which may need to be done every 3 months until resolution of the cyst occurs. There is a continued risk of fracture until the cyst heals
  • Curettage and bone grafting: the cyst is scraped out and packed with bone graft either from the patient or from a cadaver. Recommended if the cyst is very large and/or is in a weight bearing area that is likely to fracture and cause problems. (recurrence rate ~12%)
  • If there is a high risk of recurrent fracture, sometimes a metal rod is placed inside the bone to stabilize it while it heals.

• Benign but often very aggressive cyst with a high rate of recurrence despite thorough treatment
• Cyst may expand the bone and significantly weaken the structure making it easy to break
• The cyst is filled with blood
• ABC’s may be isolated, or may be associated with malignant lesions
• Symptoms: swelling, pain, may have a soft tissue mass 
• Lesions in the spine may compress the spinal cord and cause neurologic problems
• Most common age: second decade of life (10–20 years)
• Most common locations: vertebrae, femur, tibia (however, may be seen in any bone)
• In long bones, ABC’s are usually in the metaphysis of the bone
• In the spine, ABC’s are usually in the posterior elements
• X-ray findings: destructive, expansile bone lesion
• MRI findings: fluid-fluid levels indicate blood within the lesion. There are often multiple cavities and there may be an associated soft tissue mass
• Treatment:
  • Curettage (scraping the cyst out) and packing it with bone graft either from the patient or from a cadaver
  • Often requires internal fixation with metal plates or screws to prevent fracture
  • Adjuvant therapy: burring of the cyst or treatment with chemicals such as phenol

• Also referred to as Langerhans Cell Granulomatosis or Histiocytosis X
• Looks like a hole (lytic lesion) in the bone on x-ray
• Most common age: age 5-15 years
• Most common locations: skull, femur, pelvis, ribs, and spine—but any bone may be affected
• May be single or multiple
  • When there are many lesions, they may be associated with systemic diseases such as Hand-Schuller-Christian disease and Letterer-Siwe disease.
• Symptoms: pain, swelling, occasionally loose teeth or excessive thirst
• X-Ray findings: variable patterns of bone destruction, punched out lesion, periosteal reaction
  • occasionally see a “hole in a hole”
  • vertebral body may collapse creating a flat vertebrae known as vertebra plana
• Treatment:
  • Injection of solitary lesions with methylprednisolone is often curative.
  • The lesions can also be curetted and bone grafted if there is risk of fracture.
  • If there are multiple lesions or the vertebrae are involved and causing neurologic problems, systemic chemotherapy may be necessary.

Enchondroma

• Benign tumor within the medullary or center canal
• Cartilage replaces the bone in the medullary canal
• May be associated with syndromes such as Ollier’s disease and Mafucci’s syndrome.
  • There is a higher risk of malignant transformation when the enchondrmas are associated with a syndrome.
• Most common age: second decade, but may be found in any age group
• Most common location: small bones of the hands, femur and humerus
• Symptoms: often asymptomatic
  • May have pain if associated with a fracture through the weakened bone
  • Pain may also be a sign that the lesion may be malignant
• X-Ray findings: Punctate calcification within the lesion, sharp margins, expansion of the bone
• MRI findings: well circumscribed lobular lesion within the medullary canal (bright on T2, low signal on T1)
• Treatment:
  • If they are asymptomatic, the lesions can be monitored with annual x-rays and exam.
  • If they are painful or are weakening the bone, the lesions can be curetted (scraped out) and bone grafted.

• A benign “bone spur” with a cartilage cap.
• The mass or bump will grow as the child grows.
• Usually there is only one osteochondroma and the risk of cancer is nearly zero.
• There are syndromes such as multiple hereditary exostoses where the patient will have many of the masses.
  • When there are many, there is a higher risk that one may become cancerous later in life.
• Most common age: second decade of life (10-20 years)
• Most common location: around the knee and around the shoulder
• Symptoms: mass, may be painful when bumped
• X-Ray findings: the bone cortex flows into the bony protrusion, may be sessile or pedunculated
• MRI findings: cartilage cap on the bony stalk is well visualized
• Treatment:
  • If not painful, no treatment is necessary
  • If the mass is painful, very unsightly, or is growing quickly, surgical excision of the mass is recommended
    • Risks of excision: osteochondromas usually grow off of the growth plate and excising them may injure the growth plate. The bone is weak for 6-12 weeks after excision and may fracture with aggressive contact activities.

Chondroblastoma

• Benign slow growing lesion usually very close to a joint
• Most common age: 15-25 years
• Most common location: proximal humerus, distal femur and proximal tibia
• Usually in the epiphysis of the bone
• Symptoms: joint pain, often present for months to years
• X-Ray findings: well circumscribed lytic lesion, may have stippled calcification
• Treatment:
  • Curettage and bone grafting (rate of recurrence 10-20%)
    • If not Risk of surgery: the lesion is usually very close to the joint, and the lesion may collapse causing joint irregularity
  • amenable to surgery, radiation therapy can be used

• A benign tumor made up of a small nest of osteoid surrounded by osteoblasts
• Most common age: second decade (10-20 years)
• Most common in males (3 males: 1 female)
• Most common locations: proximal femur
• Symptoms: pain that is often worse at night, may be relieved by anti-inflammatory medications (Ibuprofen, Aspirin).
• X-Ray findings: small radiolucent nidus surrounded by dense reactive bone
• MRI findings: significant edema in the surrounding tissues
• CT scan: best study to visualize the nidus within the dense reactive bone
• Treatment:
  • Radiofrequency ablation can be used in some locations
  • Surgical excision of the tumor is usually curative
     

• Very common benign proliferation of fibrous tissue within a bone
• Most common age: 6-16 years
• Most common locations: distal tibia and distal femur, usually in the metaphysis
• Usually solitary 
  • If there are multiple lesions, may be associated with Jaffe-Campanacci syndrome.
• Symptoms: usually asymptomatic unless there is a pathologic fracture
• X-ray findings: Lytic metaphyseal lesions, sclerotic rim, eccentric, cortically based
• Treatment:
  • Small lesions can be observed, they resolve as patients near skeletal maturity
  • Large lesions that risk fracture can be treated with curettage and bone grafting

MALIGNANT PEDIATRIC MUSCULOSKELETAL TUMORS

• Malignant small round blue cell tumor
• Characterized by a chromosomal translocation (t11:22)(q24:12)
• Accounts for 15% of all malignant primary bone tumors
• Most common age: 5-20 years
• Most common location: pelvis and lower extremities (diaphyseal)
• Symptoms: Pain, mass, weight loss, fever
• X-ray findings: lytic or sclerotic, permeative pattern that is poorly marginated
  • Periosteal new bone formation (onion-skin or sunburst appearance)
• MRI findings: may have a large soft tissue component, long segments of medullary involvement
• Treatment:
  • Aggressive multi-agent chemotherapy
  • Complete resection of the tumor with a margin of normal tissue, which may require amputation or extensive surgical reconstruction
  • Maintenance chemotherapy
  • Radiation therapy may also be necessary

INFECTION

Symptoms of Infection:

• Pain
• Fevers
• Limp or inability to bear weight
• Decreased range of motion of a joint
• Apparent paralysis of a limb
• Loss of appetite
• Listlessness

Appointments: 
Call 858-576-5999 or 858-966-6789 for information or to make an appointment with:
 • Dr. Maya Pring (for concerns involving the arms, legs or pelvis)
 • Dr. Burt Yaszay (for concerns involving the spine)
 Click here for map to clinic

GLOSSARY

Aggressive: grows quickly and destroys tissue or bone
Aspiration: to use a needle and syringe to remove fluid (from a cyst)
Asymptomatic: no symptoms, no pain or indication that there is a problem

Benign: not cancer, does not metastasize
Bisphosphonates: medicines that prevent bone resorption
Blastic: increased density on x-ray
Bone grafting: to fill a void with bone from another part of the body (commonly from the pelvis) or from a cadaver (cadaver bone is completely sterilized and is used to create a scaffold to support new healthy bone growth)

Cafe au lait spots: large “birth marks” that are darker than the normal skin, usually with a smooth border.
Chondrosarcoma: a malignant cartilage tumor
Codman’s triangles: elevated periosteum seen on x-ray as a triangle extending away from the bone.
Cortex: the strong outside ring of bone that supports the body (the cortex is like the metal that creates a pipe, the medullary canal is the space inside the pipe)
Curettage: to surgically scrape a tumor or cyst out of the bone

Deformity: crooked or not straight
Distal: far from the body (wrist, ankle)
Diaphysis: the shaft of a bone
Diaphyseal: in the diaphysis (shaft) of the bone

Epiphysis: the area of bone proximal to the physis (growth plate) and next to the joint
Excision: to surgically remove

Fracture: break or crack in the bone

Injection: to use a needle and syringe to put fluid into the body (in this case, directly into the tumor or cyst)

Jaffe-Campanacci syndrome: multiple non-ossifying fibromas and cafe au lait spots

Localized: just in one area, not involving the entire body
Lytic: looks like a hole in the bone

Mafucci’s syndrome: Multiple enchondromas and soft tissue hemangiomas (often develop cancer later in life: chondrosarcoma, malignant brain tumors, liver and pancreatic tumors, etc)
Malignant: cancer, a tumor that has the ability to metastasize and can cause death
Mass: an abnormal growth or tumor
Mazabraud’s syndrome: fibrous dysplasia and soft tissue myxomas
McCuneAlbright syndrome: polyostotic fibrous dysplasia with skin lesions, precocious puberty, severely deformed bones
Medullary canal: the inside of a long bone (bone marrow that is inside a “pipe” of cortical bone)
Metaphysis: the area of bone just distal to the physis (growth plate)
Mataphyseal: in the metaphysis
Metastasize: to spread from one place in the body to another. This may happen through the blood or lymphatic system
Methylprednisolone: an injectable steroid that is used to treat some tumor and cysts
Monostotic: single lesion
Multiple: more than one or many lesions

Nidus: nest

Ollier’s disease: multiple enchondromas and skeletal deformity (25-50% of patients with this disease develop a low grade chondrosarcoma later in life)
Osteoblasts: cells that make bone
Osteoid: the matrix made by osteoblasts

Pathologic fracture: a fracture through an area of bone weakened by a tumor or cyst
Periosteum: the thin flexible lining around the bone
Physis: growth plate
Polyostotic: multiple lesions
Proximal: close to the body (hip, shoulder)

Radiofrequency ablation: a probe is inserted into the center of a lesion through a small incision and high frequency current heats up the tumor cells and destroys them.

Sclerotic: increased density of bone seen on x-ray
Skip lesions: multiple discrete tumor in the same bone
Solitary: just one lesion
Symptom: a sign that something is wrong (pain, swelling)
Systemic: involves the whole body

Translocation: a mutation where parts of 2 chromosomes are switched
Tumor: abnormal growth of cells, may be benign or malignant

Additional information can be found by clicking the following links:

• General Information
• Partners
• Information about Osteosarcoma
• Information about Ewing’s Sarcoma

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