Does osteofibrous dysplasia progress to adamantinoma and how should they be treated?

AIMS: The aim of this study was to identify any progression between benign osteofibrous dysplasia (OFD), OFD-like adamantinoma and malignant adamantinoma, and to investigate the rates of local recurrence, metastases and survival, in order to develop treatment algorithms for each. PATIENTS AND METHODS: A single institution retrospective review of all patients presenting with OFD, OFD-like adamantinoma and adamantinoma between 1973 and 2012 was undertaken. Complete data were available for 73 patients (42 with OFD; ten with an OFD-like adamantinoma and 21 with an adamantinoma). The mean follow-up was 10.3 years (3 to 25) for OFD, 9.2 years (3.0 to 26.3) for OFD-like and 11.6 years (0.25 to 33) for adamantinoma. RESULTS: The mean age at diagnosis for OFD was 13.5 years (1 to 49), 10.5 years (6 to 28) for OFD-like and 34 years (14 to 86) for adamantinoma. A total of 24 of the 42 patients with OFD (57%) have not required any treatment and have been managed with observation. A total of 18 of the 42 patients with OFD underwent surgery, 13 with curettage and five with resection. In all, three patients developed recurrence following curettage (23%) but none following resection. All these patients were cured with further limited surgery. A total of six patients initially diagnosed with OFD were subsequently found to have OFD-like adamantinoma. Of the ten patients initially diagnosed with OFD-like adamantinoma, three (30%) were managed with observation alone and seven underwent surgery, two with curettage and five with resection. Local recurrence arose in two patients, one each after curettage and resection. No patients with either OFD or an OFD-like adamantinoma developed metastases or had progression to adamantinoma. All patients with an adamantinoma were treated by surgery, three with curettage, six with amputation and 12 with excision. In all, two of the three treated with curettage developed local recurrence, requiring further surgery. Late development of both local recurrence and metastases led to a ten year disease specific survival of 93% which had dropped to 39% by 20 years. CONCLUSION: We found no evidence of progression from OFD to adamantinoma. Conservative management with observation or curettage is often successful for patients with OFD and OFD-like adamantinoma. Resection with clear margins is required for patients with adamantinoma. Late tumour recurrence is not uncommon in adamantinoma and prolonged follow-up should be considered. Cite this article: Bone Joint J 2017;99-B:409-16.

Ewing-like adamantinoma.

The Ewing-like variation of adamantinoma is a rare entity, leading to challenge its differential diagnosis, notably with Ewing's sarcoma. We are reporting a case of a 20-year-old male who presented with swelling in the left leg that had progressed over a 2-year period. X-rays revealed a tumour in the tibia that was intracortical, osteolytic, multilocular and invaded the soft tissues. A surgical biopsy was performed. Histopathology examination showed a tumour growth with small round cells expressing CD99. A diagnosis of Ewing's sarcoma was made. Since the patient declined surgical treatment, chemotherapy was administered. Two years later, the patient returned because the tumour had grown in size. A second biopsy was performed. Microscopic evaluation showed a tumour growth with osteofibrous and epithelial components, which expressed pankeratin and vimentin, but was negative for CD99. A diagnosis of Ewing-like adamantinoma was made.

Adamantinoma of tibial shaft.

Adamantinoma is an extremely rare primary bony neoplasm. Because of its malignant nature, accurate and early diagnosis is very important. On the other hand adamantinoma mimics many benign conditions, so it is doubly important to establish correct tissue diagnosis to avoid radical surgery with morbidities. Because of its rarity, diagnosing adamantinoma still remains difficult, even if when it occurs in classical sites. We report a case of adamantinoma of tibial shaft diaphysis in a 23 year male. In this case, because of classic clinic-radiological features, we were suspecting adamantinoma from very beginning but final diagnosis was delayed for nine months.

Adamantinoma of the calcaneum--a case report.

Adamantinoma is rare, representing less than 1% of all primary malignant bone tumours. It is a slow growing low grade malignant tumour which is often clinically, radiologically and histologically mistaken for many other tumours like Ewing's sarcoma, synovial sarcoma, fibrosarcoma, metastatic carcinoma, fibrous cortical defect and osteofibrous dysplasia. Adamantinoma commonly occurs in the tibia. It is also known to occur in the fibula, femur, humerus, radius and ulna. Adamantinoma of the foot is extremely rare. There are few reported cases of metatarsal and cuneiform bone involvement. To our knowledge adamantinoma of the calcaneum has not been previously reported in the literature. We report the case of a male patient, aged 33 years, who was treated for adamantinoma of the calcaneum and followed for 16 years highlighting the difficulty in diagnosis and management of this rare tumor occurring at a rare site.