M. Forest

Clear-cell chondrosarcoma A report of five cases including ultrastructural study

Five cases of clear‐cell variant of chondrosarcoma (Unni et al.16) are reported. The tumors occurred in the epiphyseal region of long bones; three in the femoral head. Roentgenographically, the lesion was usually a well‐defined and benign appearing one, either purely lytic (3 cases) or with central radiodensity (2 cases). Histologically, all five cases had areas of conventional chondrosarcoma; however, the greater portion of the tumor was made up of sheets of clearcells intermixed with nonneoplastic bone trabeculae but devoid of chondroid matrix. Electron microscopic studies showed that these clear‐cells possess cytoplasmic microvilli, abundant glycogen particles and prominent golgi complexes, like normal or tumorous chondroid cells usually have. In our experience, the best treatment seemed to be en bloc resection with joint replacement; indeed, despite the fact that they are true chondrosarcomas, these tumors usually have a very slow rate of growth. Cancer 44:622‐629, 1979.

Malignant Fibrous Histiocytoma at the Site of a Previously Treated Aneurysmal Bone Cyst: A Case Report

Jaffe and Lichtenstein1 described aneurysmal bone cyst as a benign non-neoplastic lesion of unknown etiology. Aneurysmal bone cysts can be primary or secondary to other bone tumors, including nonossifying fibroma, chondroblastoma, giant-cell tumor of bone, osteoblastoma, fibrous dysplasia, fibromyxoma, osteoblastoma, solitary bone cyst, hemangioendothelioma, osteosarcoma, and metastatic carcinoma2,3. Although several cases of malignant transformation have been reported, most were either radiation-induced sarcomas or telangiectatic osteosarcomas that had been misdiagnosed as aneurysmal bone cyst. To our knowledge, the literature contains only one report of satisfactorily documented malignant transformation of an aneurysmal bone cyst4. We describe a patient who had a malignant fibrous histiocytoma at the site of a femoral aneurysmal bone cyst that had been treated twelve years earlier by curettage and internal fixation after a pathological fracture. A twenty-eight-year-old man was admitted to our institution in December 1986 because of a pathological supracondylar fracture of the left femur. Anteroposterior and lateral tomograms revealed a pathological fracture in the distal part of the left femur through a large lytic lesion in the diaphysis and epiphysis (Fig. 1). There was no periosteal reaction. The limb was placed in an above-the-knee cast. No evidence of metastasis was seen on a computed tomographic scan of the chest, and a technetium-99m polyphosphate bone scan showed a single focus of hyperactivity only at the site of the pathological fracture. Routine laboratory data were normal. Fig. 1: Tomograms showing the pathological fracture through the aneurysmal bone cyst. An open biopsy of the femoral lesion was performed. Histological examination revealed the typical features of an aneurysmal bone cyst, with multiple blood-filled cavities separated by fibrous septa containing osteoid, giant cells, and fibroblasts (Figs. 2-A and 2-B). Fig. 2-A: Fig. 2-A Photomicrograph of the aneurysmal bone cyst, showing septa delimiting cavernous spaces filled with blood …

Frequency and diagnostic value of the virus-like filamentous intranuclear inclusions in giant cell tumor of bone, not associated with Paget's disease: a study of 43 cases

This paper deals with the paramyxovirus-like intranuclear inclusions observed in giant cells tumours of bone (GCTB). Twenty-one (49%) of 43 cases of GCTB (1977–1985), either fresh and/ or cultured, show these ultrastructural inclusions. Fifty samples of various bone lesions in which giant cell lesions occurred, including aneurysmal cysts, hyperparathyroidism, osteoblastoma, human and rat osteopetrosis, GCT of tendon sheaths, and non skeletal granuloma were used as controls. These, together with 20 samples of normal bone (osteoclasts) did not contain intranuclear or intracytoplasmic viral inclusions.