["Adamantinoma" of the tibia and reactive bone changes (author's transl)]

Osteofibrous dysplasia and adamantinoma in children and adolescents: a clinicopathologic reappraisal

Osteofibrous dysplasia (OFD) and adamantinoma are rare and most commonly arise in the tibia of young individuals. Although OFD has typical histopathologic features, areas resembling OFD have often been noted at the periphery of otherwise classic adamantinomas, and some have suggested that OFD may be either a precursor to or a regressive phase of adamantinoma. The so-called OFD-like adamantinoma encompasses some features of both OFD and adamantinoma. We studied the clinical, imaging, histopathologic, immunohistochemical, ultrastructural, and molecular features of 16 OFD and 8 adamantinomas (5 OFD-like and 3 classic) in an attempt to further define their morphology, clinical course, and relationship. Patients with OFD were generally younger than those with adamantinoma. Osteoblastic and osteoclastic activity was more prominent in OFD than in OFD-like adamantinoma. In addition to the inconspicuous small clusters of epithelial cells in OFD-like adamantinoma, isolated keratin-positive cells with a unique ultrastructural hybrid fibroblastic-epithelial phenotype were found in the stroma of all OFD and OFD-like adamantinomas. Fluorescence in situ hybridization analysis revealed trisomies 7, 8, and/or 12 in the spindle cell stroma of OFD, OFD-like, and classic adamantinoma, supporting a neoplastic origin of OFD and a common histogenesis for all 3 lesions. Trisomies were not observed in osteoblasts or osteoclasts suggesting that the osseous component is reactive and non-neoplastic. Of the 11 OFD patients with follow-up (median, 4.5 y), all 3 who underwent incisional biopsy had persistent, nonprogressive disease and 2 of 8 who underwent curettage or wide excision had recurrence; none developed adamantinoma. All 6 adamantinoma patients with follow-up (3 classic and 3 OFD-like) were treated with wide excision. One with classic adamantinoma died of pulmonary metastases 9 years after presentation; the other 5 were free of disease with a median follow-up of 12 years. None of the classic adamantinomas evolved into OFD-like adamantinoma or OFD. Although the histopathology, immunohistochemistry, ultrastructure, and cytogenetics indicate that these lesions are closely related, our data and the literature suggest that only classic adamantinoma has malignant potential. OFD, OFD-like adamantinoma, and classic adamantinoma appear to show a progressive complexity of cytogenetic aberrations, perhaps indicative of a multistep neoplastic transformation.

Adamantinoma of the spine: case report

OBJECTIVE

We report a patient with a cervicothoracic spinal and a mandibular adamantinoma. Adamantinoma is a rare malignant neoplasm of bone and, to our knowledge, there have been only five cases of spinal adamantinoma reported. The pathogenesis of the adamantinoma, as well as the management of this extremely rare spinal tumor, is reviewed.

CLINICAL PRESENTATION

A 55-year-old man was admitted to our service with cervical pain and signs of C8 and T1 radiculopathy. On physical examination, cervical spine deformity, swelling in the left mandible region, and signs of C8 and T1 radiculopathy were observed. Neuroradiology examinations showed an osteolytic mass of the C6, C7, and T1 vertebral bodies, extending into the lateral masses and transverse processes. After surgical procedures, the patient had clinical improvement.

INTERVENTION

Corpectomy of C6, C7, and T1 was performed through a cervicothoracic anterior approach. Anterior stabilization of the spine was obtained using an autologous iliac crest graft and osteosynthesis with an anterior plate. On a second procedure, posterior tumor resection and spinal stabilization were performed. After the 1-year follow-up examination, a new anterior procedure was performed because of tumor recidivity and spine instability.

CONCLUSION

Adamantinoma, an extremely rare lesion, is a locally aggressive tumor with slow growth and the potential to metastasize. Although it is an extremely rare occurrence in the spine, adamantinoma should be considered on the diagnosis of tumors of the vertebrae. Neuroradiological examinations are not specific in the differentiation of this tumor from other conditions. This fact, coupled with the limited experience that most physicians in general have in dealing with this tumor, makes the diagnosis and treatment of adamantinoma challenging.

Adamantinoma, osteofibrous dysplasia and differentiated adamantinoma

For just over 100 years, adamantinoma has been recognized as a primary bone tumor with epithelial characteristics and predominantly involving the tibia. Osteofibrous dysplasia is a fibro-osseous lesion also predominantly confined to the tibia with radiologic features similar to those of adamantinoma. This lesion has been shown by immunohistochemical studies to frequently contain cytokeratin-positive epithelial cells. More recently, a third group of cases with clinical and radiologic features similar to those of osteofibrous dysplasia have demonstrated more overt strands of epithelial cells within a fibro-osseous background and have been categorized as "differentiated", "regressive", "juvenile intracortical" or "osteofibrous dysplasia-like" adamantinoma. Cytokeratin subset immunohistochemical stains and cytogenetic studies performed in recent years suggest a common histogenesis for these three entities. This article reviews the clinical, radiologic and pathologic features of these entities as well as their prognostic significance. It also reviews the results of the immunohistochemical and cytogenetic studies which establish a common histogenetic relationship.