Adamantinoma

Adamantinoma - intermed mag[1]

Adamantinomas are rare, slow growing malignant bone tumors, which occurs almost exclusively in the long bones.

Presentation

One of the most common traits of this tumor is its predilection for the long bones. It occurs here in 97% of cases. On the long bones, it focuses on the tibia in 80% -85% of cases. It is therefore its most characteristic clinical feature [5]. In 10% to 15% of cases, the lesion is seen in the ipsilateral fibula. Statistically, this tumor remains prevalent in the tibia but other limb bones have been involved. The involvement of several short bones has been reported on rare occasions as well. In other of decreasing frequency, some other bones that have been involved at appoint or the other includes:

  • The humerus
  • The ulna
  • The femur
  • The fibula
  • The radius
  • The innominate bones
  • The ribs
  • The spine
  • The small bones of the hand and foot


Only six case of spinal adamantinoma have been reported till date [6]. There have also been rare reports of adamantinomas arising exclusively from the pretibal soft tissues without any bony involvement. The initial symptoms of adamantinomas are usually indolent and non-specific.

They are also dependent on the location and extent of the disease. The onset of the disease is insidious and the course shows a slow progressive character.

In many cases the patients endure years of pain before seeking medical attention. In 60% of reported cases, trauma is common place. Apart from the pain reported, many patients also show swelling. The swelling may also be there without the pain.

Due to the involvement of the anterior tibial surface, patients may present bowing deformity of the fibia [7]. In as many as 23% of patients, pathological fracture was present. Other rare cases show paraneoplastic hypercalcemia (linked with tibial adamantinoma) and pulmonary metastasis. In addition to the pain spinal lesions may be manifested by neurologic symptoms.

Workup

Radiographs are used for confirmatory purposes and they show many lucent lesions that are sharply circumcised. There is often interspersed sclerotic bone in mid tibia. Some lesions also destroy cortex. Bowing of the tibia may be seen as well. The radiographic evolution of lesions often proves helpful in diagnosis as lesions continue to grow and erode through the cortex [8]. Unlike what is seen in most primary bine tumors, adamantinoma doesn’t show any periosteal reaction.

Histological studies are carried out as well and they show fibrous and epithelial tissue in gland like pattern characteristically. Epithelial and mesenchymal cells will be visible too as well as nests of epithelial-like cells arranged in palisading or glandular pattern. A background of fibrous stroma is also common.

Treatment

Generally, treatment involves wide resection or amputation. During the course of the disease metastases may occur. This occurs in 30% of cases even though it is rare at presentation. Prognosis and response to treatment is great but the chances are lower when a wide surgical margin cannot be obtained.

Chemotherapy does not work as the tumor is not sensitive to radiation [9]. The only time when chemotherapy is deployed is when the cancer has spread to the lungs or other sensitive organs.

Prognosis

In 25% of cases reported, adamantinomas metastasized into the lungs. This is why long-term followup is highly recommended [4]. With negative margin excision, recurrence is rarely recorded. Majority of children treated surgically for adamantinoma have very positive long term outlook. Their 10 year survival rate is placed around 85%.

Etiology

The etiology of the tumor is not known and this has added to the controversy surrounding its origin.

Epidemiology

The condition is very rare and so, less than 300 cases have been recorded in the past century [2]. Of the documented cases, it has been established that the condition occurs majorly in young adults who are 20-40 years of age.

Sex distribution
Age distribution

Pathophysiology

Adamantinomas are classified into two main types, the classic and differentiated. Classic adamantinomas is seen in patients already older than 20 years of age but differentiated adamantinomas happen in patients younger than 20. Additionally, these two classifications have distinctive radiographic and histologic differences.

Adamantinoma patients often show varying signs and symptoms. Generally, they report swelling and pain. Since the tumor grows rather slowly, patients often describe discomforts that may have lasted for months or years. Even though it is difficult to figure out an accurate mortality statistics due to the rarity of the tumor, there is 10% 10-year survival rate [3]. When faced with this tumor, medical professionals carry out surgeries which may include either marginal or en bloc resection. Traditional therapy and chemotherapy have not proven effective regarding the effective treatment of the disorder.

Prevention

There are no proven ways to prevent this but regular exercise of the lower extremities and bone friendly nutrition is recommended.

Summary

Adamantinoma is a rare type of tumor and till date, the origin remains a controversial topic. The tumor was first described by Fischer in 1913 [1] and till date, less than 300 cases have been reported. The tumor occurs almost exclusively within the long bones and in 80% of cases, tumors occur in the tibia. The most commonly affected is the diaphyseal region.

Patient Information

Patients are advised to cooperate with medical personnel and accept any procedures recommended by them. Adamantinoma doesn’t respond to chemotherapy, radiation etc. So surgery is the treatment method in most cases [10]. The different types of surgery are:

  • Limb salvage surgery: This focused on helping preserve the limb by removing the tumor and some of the healthy tissue surrounding it.
  • Amputation: This will only be carried out if the tumor involves any major nerves or blood vessels.

If the adamantinoma reoccurs, more surgery will be required.
Healthy individuals are encouraged to immediately report any pain in the lower extremities that have lasted more than a week. This condition must not be confused with arthritis.

Self-assessment

References

  1. Fischer B. Uber ein primares Adamantinom der Tibia. 12. Frankfurt: Zeitschr. f. Path.; 1913:422-441.
  2. Van Rijn R, Bras J, Schaap G, Van den Berg H, Maas M: Adamantinoma in childhood: report of six cases and review of the literature. Pediatr Radiol 2006, 36:1068-74.
  3. Mirra JM: Adamantinoma and fibrous dysplasia. In Bone tumors. 1st edition. Edited by Mirra JM. Lea & Febiger, Philadelphia; 1989:1203-1231.
  4. Fisher B: Primary adamantinoma of the tibia. Z Pathol 1913, 12:422-441.
  5. Schulenburg CA: Adamantinoma. Ann R Coll Surg Engl 1951, 8:329-353
  6. Ryrie BJ: Adamantinoma of the tibia: aetiology and pathogenesis. BMJ 1932, 2:1000-1003
  7. Baker PL, Dockerty MB, Coventry MB: Adamantinoma (so-called) of the long bones. J Bone Joint Surg Am 1954, 36-A:704-20.
  8. Yildiz C, Erler K, Atesalp AS, Basbozkurt M. Benign bone tumors in children. Curr Opin Pediatr 2003; 15:58.
  9. Wyers MR. Evaluation of pediatric bone lesions. Pediatr Radiol 2010; 40:468.
  10. Springfield DS, Gebhardt MC. Bone and soft tissue tumors. In: Lovell and Winter's Pediatric Orthopaedics, 6th, Morrissy RT, Weinstein SL (Eds), Lippincott Williams & Wilkins, Philadelphia 2006. p.493.
  11. Faivre L, Nivelon-Chevallier A, Kottler ML, et al. Mazabraud syndrome in two patients: clinical overlap with McCune-Albright syndrome. Am J Med Genet 2001; 99:132.



Media References

  1. Adamantinoma - intermed mag, CC BY-SA 3.0