Adamantinoma (from the Greek word ''adamantinos'', meaning "very hard") is a rare

bone cancer A bone tumor is an abnormal growth of tissue in bone, traditionally classified as noncancerous (benign) or cancerous (malignant). Cancerous bone tumors usually originate from a cancer in another part of the body such as from lung, breast, thy ...

, making up less than 1% of all bone cancers. It almost always occurs in the bones of the lower leg and involves both

epithelial Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercell ...

and osteofibrous tissue. The condition was first described by Fischer in 1913.

Presentation

Patients typically present with swelling with or without pain. The slow-growing tumor predominantly arises in long bones in a subcortical location (95% in the

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

fibula The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity i ...

). Most commonly, patients are in their second or third decade, but adamantinoma can occur over a wide age range. Benign osteofibrous dysplasia may be a precursor of adamantinoma or a regressive phase of adamantinoma. Histologically, islands of epithelial cells are found in a fibrous stroma. The tumor is typically well-demarcated,

osteolytic Osteolysis is an active resorption of bone matrix by osteoclasts and can be interpreted as the reverse of ossification. Although osteoclasts are active during the natural formation of healthy bone the term "osteolysis" specifically refers to a path ...

and eccentric, with cystic zones resembling soap bubbles.

Diagnosis

Diagnosis is on plain radiography, or CT scan

Treatment

Treatment consists of wide resection or amputation. Metastases are rare at presentation but may occur in up to 30% of patients during the disease course. Prognosis is excellent, with overall survival of 85% at 10 years, but is lower when wide surgical margins cannot be obtained. This tumor is insensitive to radiation so

chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...

is not typically used unless the cancer has

metastasized Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...

to the lungs or other organs.

History

The typically benign odontogenic tumor known as

ameloblastoma Ameloblastoma is a rare, benign or cancerous tumor of odontogenic epithelium ( ameloblasts, or outside portion, of the teeth during development) much more commonly appearing in the lower jaw than the upper jaw. It was recognized in 1827 by Cusack ...

was first recognized in 1827 by Cusack but did not yet have any designation. In 1885, this kind of odontogenic neoplasm was designated as an ''adamantinoma'' by Malassez and was finally renamed to the modern name ''

'' in 1930 by Ivey and Churchill. Some authors still confusingly misuse the term adamantinoma to describe ameloblastomas, although they differ in histology and frequency of malignancy.

References

External links

{{Osseous and chondromatous tumors Rare cancers Osseous and chondromatous neoplasia