Orthopedic Oncology cases adamantinoma

An 18-year-old male presents to your office with pain in his lower right leg and an enlarging mass over the anterior tibia. These symptoms have been worsening for the past 3 months. His pain waxes and wanes and tends to be associated with physical activity, and he is training for a marathon so he is quite anxious about this. He has tenderness over the subcutaneous border of the tibia, and has a palpable mass there that is fixed to the bone. X-rays are shown in Figure 8–38A and B.

 

 

Figure 8–38 A–B

 

What is the most likely diagnosis?

1. Osteosarcoma

2. Enchondroma

3. Tibial stress reaction

4. Adamantinoma

 

Discussion

The correct answer is (D). Adamantinoma is a rare low-grade malignant bone tumor that occurs almost exclusively in the tibia. It can cause pain and tenderness in the anterior tibia and has a classic “soap-bubble” appearance on x-ray. A similar but benign lesion is osteofibrous dysplasia, and these tumors are considered to be on either end of a spectrum of disease of the same etiology.

Appropriate workup is performed and he is diagnosed with adamantinoma. What is the appropriate management of this patient?

1. Radiation therapy

2. Wide surgical resection

3. Radiation prior to wide surgical resection

4. Above-knee amputation

 

Discussion

The correct answer is (B). Standard of care is wide surgical resection with reconstruction. Given the diaphyseal location of most adamantinoma, intercalary grafting is commonly performed. Chemotherapy and radiation are not indicated in this condition, and local recurrence is associated with positive margins at the time of resection.

Objectives: Did you learn...?

 

 

To recognize adamantinoma and its relative osteofibrous dysplasia? Treatment of adamantinoma?