Adamantinoma

Descripción general

Adamantinoma is a rare bone cancer. It's a tumor of long bones that most often develops in the shinbone, also called the tibia. It also may involve the fibula, another bone in the lower leg. Rarely, it develops in other long bones. One type of adamantinoma, called classic adamantinoma, often grows slowly. But it can return after treatment or spread to other parts of the body.

Long-bone adamantinoma is different from ameloblastoma. Ameloblastoma is a separate tumor that develops in the jaw.

Types

The main types of adamantinoma are classic adamantinoma, osteofibrous dysplasia-like adamantinoma and dedifferentiated adamantinoma. Osteofibrous dysplasia-like adamantinoma also may be called differentiated adamantinoma.

Classic adamantinoma

Classic adamantinoma is a cancerous bone tumor. This type can return where it started or spread to other parts of the body. It most often affects adults.

Osteofibrous dysplasia-like adamantinoma

An osteofibrous dysplasia-like adamantinoma has small groups of tumor cells scattered within tissue that resemble osteofibrous dysplasia. This is a separate bone condition.

Because the tumor cells are scattered, it can be hard to diagnose osteofibrous dysplasia-like adamantinoma. A small tissue sample taken in a biopsy may not contain these tumor cells, which can make diagnosis difficult. This type can return in the affected bone. Studies that have evaluated this type haven't reported spread to distant parts of the body. This type tends to be diagnosed at younger ages than classic adamantinoma.

Dedifferentiated adamantinoma

Dedifferentiated adamantinoma is very rare. Part of the tumor has cells with more-aggressive features under a microscope. This type also may act more aggressively than classic adamantinoma.

How adamantinoma differs from osteofibrous dysplasia

Osteofibrous dysplasia is different from adamantinoma because osteofibrous dysplasia is a separate bone tumor that isn't cancer. It usually starts in childhood.

Osteofibrous dysplasia, osteofibrous dysplasia-like adamantinoma and classic adamantinoma can look similar in imaging tests and tissue samples. But they have differences, and it's important to diagnose each of these specific conditions as each one may have different treatments and outlooks. Researchers continue to study how these three conditions are related. Studies haven't shown that osteofibrous dysplasia changes into classic adamantinoma. Depending on the quality of tissue samples used, the diagnosis may change from one to the other after more biopsies or tissue exams.

Síntomas

Adamantinoma symptoms may develop gradually. They can include:

• Pain in one area, often along the shin.
• Swelling near the affected bone.
• A lump or bulge over the affected bone.
• A limp or trouble putting weight on the affected leg.
• A break, also called a fracture, in a bone weakened by the tumor.
• Bowing or another change in the shape of the lower leg.

The way a lump looks or feels isn't enough to confirm adamantinoma. A lump can have many other causes. Imaging tests can show whether the lump involves bone. But a biopsy is needed to confirm that the lump is caused by adamantinoma.

Shin pain can have many causes, such as shin splints or a bone tumor. Symptoms alone don't give enough information to diagnose the cause.

When to seek care

Make an appointment with a healthcare professional if bone pain lasts, gets worse or happens at night. Also make an appointment if you have swelling or an unexplained lump over a bone. These symptoms can have many causes. Your healthcare professional may suggest imaging tests to find the cause.

Causas

The cause of adamantinoma isn't known. Researchers continue to study how the tumor starts and how adamantinoma may be related to osteofibrous dysplasia.

Studies have not shown that adamantinoma is inherited, meaning passed from a parent to a child.

Factores de riesgo

Risk factors for adamantinoma aren't known. No proven link has been found between adamantinoma and exposure to chemicals, radiation or particular activities. Classic adamantinoma is most often diagnosed in young and middle-aged adults. Osteofibrous dysplasia-like adamantinoma tends to be diagnosed at younger ages, including in children and teens.

Studies don't consistently show that adamantinoma affects one sex more often.

Complicaciones

Adamantinoma can weaken the affected bone and cause it to break. The tumor also may grow beyond the bone into nearby soft tissues. Classic adamantinoma can spread to other parts of the body, most often the lungs.

Care team

Care for adamantinoma generally involves a team with experience treating bone tumors. The team may include many specialists in the following areas.

• Orthopedic oncology.
• Musculoskeletal radiology.
• Bone pathology.
• Medical oncology.
• Radiation oncology.
• Rehabilitation.

Other specialists may be involved based on the tumor's location, whether it has spread and the treatment needed.