Fibrogenesis imperfecta ossium (Baker's disease): a case studied at autopsy.

A man aged 40 years showed radiographic changes in the form of generalized increased bone density and patchy rarefaction. Urinary calcium was increased and serum alkaline phosphatase was elevated; serum calcium and phosphate levels were normal. Multiple fractures developed. At autopsy, all parts of the skeleton showed partial replacement of bone and bone marrow by a tissue deficient in collagen fibers. Much of this tissue was unmineralized, but lesions in cortical bone showed hypermineralization on microradiographic examination. Electron microscopy showed replacement of collagen fibers by amorphous material in the affected areas. Electron probe analysis showed a normal Ca:P ratio for bone mineral in the hypermineralized areas.

Fibrous dysplasia of bone: case report with autopsy study 80 years after the original clinical recognition of the bone lesions.

We present a report of the histological features of the bone lesions in a case of polyostotic fibrous dysplasia studied at autopsy in a patient aged 88 years. While much of the fibrous tissue of the lesions contained the trabeculae of non-lamellar bone that are a feature of fibrous dysplasia in young patients, other parts of the lesions showed evidence of osteoclastic remodelling of bone trabeculae, and even of the replacement of some of these structures by mature lamellar bone.

The World Health Organization's histologic classification of bone tumors. A commentary on the second edition.

BACKGROUND: The World Health Organization's histologic classification of bone tumors was revised in 1993. METHODS: The first edition was reviewed by an international panel of pathologists from nine countries and modified to incorporate advances made in the twenty years since it appeared. RESULTS: The framework and concept of the classification remain the same (i.e., based on histologic criteria in terms of differentiation shown by the tumor cells via conventional light microscopy supplemented by immunohistochemistry). New entities not described in the first edition include, for example, benign and malignant fibrous histiocytomas, well differentiated osteosarcoma, round-cell osteosarcoma, clear cell chondrosarcoma, primitive neuroectodermal tumor of bone, osteofibrous dysplasia, and giant cell reparative granuloma. CONCLUSION: The revised and expanded classification reflects advances in our knowledge, but is similar in concept and framework to the original version to allow comparisons between data collected in the past and future.

Calcified spherules in fibro-osseous lesions of bone.

We present 20 examples of fibro-osseous lesions of bone, characterized by the presence of varying numbers of rounded calcified structures (calcified spherules). In the past, such lesions have been regarded as ossifying fibromas or cementifying fibromas, the latter because of their histologic similarity to jaw lesions known by that name. In the present series, six lesions showed, in addition to the calcified spherules, typical histologic features of fibrous dysplasia, while a further seven showed atypical bony structures that also suggest a link with fibrous dysplasia. This study has led us to conclude that these lesions of the extragnathic skeleton, containing rounded calcified spherules, represent a variant of fibrous dysplasia.

Membranous bone lengthening: a serial histological study.

Bone lengthening using the process of corticotomy and gradual distraction of callus is applicable to the membranous bone of the canine mandible. In this study the precursors to bone formation, in the area between the distracted bone edges, are analyzed in an attempt to determine the mechanism of bone formation. Ten mongrel dogs 5 months of age were studied. A unilateral, periosteal-preserving angular corticotomy was performed, and an external bone-lengthening device was fixed to the mandible. After 10 days of external fixation, the mandible was lengthened 1 ml per day for 20 days and then held in external fixation for 8 weeks. The dogs were killed for histological and microradiographic study at 10 and 20 days of distraction, and at 14, 28, and 56 days after the completion of distraction. It was observed that the gap between the distracted bone edges is first occupied by fibrous tissue. As distraction proceeds, the fibrous tissue becomes longitudinally oriented in the direction of distraction. Early bone formation advances along the fibrous tissue, starting from the cut bone ends. Eventually the area is converted to mature cortical bone. Bone is formed predominantly by intramembranous ossification. This mechanism is similar to that of bone formation during long bone lengthening.

Pathology of osteonecrosis of the femoral head. A review of experience at the Hospital for Joint Diseases, New York.

Pathological examination of the resected femoral heads from approximately 2000 total hip replacement operations carried out at the Hospital for Joint Diseases from 1984 to 1989 identified the presence of osteonecrosis in 345 patients (377 femoral heads). In 232 patients the osteonecrosis, referred to as "idiopathic," had occurred in the absence of a subcapital fracture. The present paper describes the pathology of the necrotic lesions in these 232 patients. The use of undecalcified sections and microradiography provides evidence of bone marrow calcification which, at the margin of the lesion, is sufficient to influence the radiographic features of the lesion significantly. Although a subchondral fracture is an almost constant feature of osteonecrosis when it occurs in a femoral head with a normal articular cartilage, no such fracture was found in cases in which osteonecrosis had occurred in an osteoarthritic joint.

Case report 662. Bilateral avascular necrosis of femur, with supervening suppurative arthritis of right hip.

We present a case of suppurative arthritis occurring in a patient with bilateral osteonecrosis of the femoral head. Predisposing factors were chronic alcoholism (osteonecrosis) and septicemia due to intravenous drug abuse (suppurative arthritis). Although the association of suppurative arthritis and osteonecrosis is rarely reported in the literature, the prevalence of osteonecrosis and of various factors predisposing to the development of suppurative arthritis should remind us of the possibility that a patient with osteonecrosis who develops sudden worsening of joint pain or fever may have developed suppurative arthritis of the affected joint, particularly when there is evidence of bone destruction.

Bone lengthening in the craniofacial skeleton.

The process of bone lengthening by cortical fracture and gradual distraction of callus has become well established in the enchondral bones of the extremities. In this study the principles of bone lengthening were applied to the membranous bone of the craniofacial skeleton using the growing dog mandible as a model. Six mongrel dogs five months of age were studied. A unilateral, periosteal-preserving angular corticotomy was performed, and an external minilengthening device was fixed to the mandible perpendicular to the corticotomy. After 10 days of external fixation, the mandible was lengthened 1 mm/day for 20 days and then held in external fixation for 56 days (8 weeks) after which all dogs were killed. Anthropometric measurements and histological analysis of the specimens confirmed that bone lengthening had occurred and that new cortical bone was formed in the expanded areas.

A light and scanning electron microscopic study of osteocyte activity in calcium-deficient rats.

The material herein is an extension of an earlier study of osteocyte lacunae in calcium-deficient rats, utilizing morphometric measurements in undecalcified bone sections and scanning electron microscopy. The results confirm our earlier finding that bone resorption resulting from a low-calcium diet is not accompanied by osteocytic resorption.

The role of rigid skeletal fixation in bone-graft augmentation of the craniofacial skeleton.

The type of fixation (rigid skeletal vs. wire) was assessed against embryologic origin (membranous vs. endochondral) and recipient site (depository vs. resorptive) as variables affecting inlay and onlay bone-graft survival in 20 mature dogs. Wet weight and volume measurements were made at operation and at sacrifice (16 weeks). The results were as follows: (1) Rigid skeletal fixation increased bone-graft volume survival over wire fixation (p less than 0.05). (2) Fixation (i.e., rigid skeletal) and embryologic origin (i.e., membranous) were equal determinants of bone-graft volume survival (p less than 0.001); the recipient site was not significant for onlay bone graft survival. (3) Embryologic origin was the only significant determinant of weight survival (p less than 0.001). (4) Inlay bone grafts demonstrated greater weight and volume survival than onlay bone grafts (p less than 0.05). (5) Histologic and microradiographic studies demonstrated bony union of bone grafts fixed with rigid skeletal fixation, while fibrous union predominated in bone grafts fixed with wire technique.

Tumoral calcium pyrophosphate deposition disease.

A report of two patients in which a soft tissue mass, initially regarded as a malignant tumor, was shown to be the result of calcium pyrophosphate deposition disease. The first case, a woman aged 71 years, presented with a mass involving the right fifth finger. In the second case, also a woman aged 71 years, the lesion involved the tissues adjacent to the right hip. Each lesion consisted of a mass of highly cellular tissue containing deposits of calcium pyrophosphate dihydrate crystals. The clinical, radiological, and pathological features of the two cases are compared with those of seven similar cases reported in the literature.

Aneurysmal bone cyst. A review of 123 cases including primary lesions and those secondary to other bone pathology.

A group of 639 bone lesions was reviewed in order to study the features of the aneurysmal bone cyst and its association with other conditions. A diagnosis of primary aneurysmal bone cyst not associated with any other bone lesion was made in 87 patients. In 36 additional patients the gross and microscopic changes of aneurysmal bone cyst were identified as part of some other solid bone lesion. Fourteen of these additional cases were associated with giant cell tumor (96 cases studied), six with chondroblastoma (41 cases studied), three with chondromyxoid fibroma (45 cases studied), two with nonossifying fibroma (68 cases studied), four with osteoblastoma (61 cases studied), one with fibrosarcoma (50 cases studied), three with fibrous histiocytoma (45 cases studied), two with osteosarcoma (100 cases studied), and one with fibrous dysplasia (42 cases studied). The age, site, and sex distribution of the cases associated with another lesion compares closely with that of the solid lesion concerned, supporting the concept that the aneurysmal bone cyst component is secondary.

Malignant transformation of fibrous dysplasia. A case report and review of the literature.

A 34-year-old man developed a spindle-cell sarcoma originating in a preexisting lesion of monostotic fibrous dysplasia. A review of the literature reveals 83 cases of a malignant degeneration in fibrous dysplasia; osteosarcoma was the most common type of tumor. The next most common were fibrosarcoma and chondrosarcoma. The malignant tumor usually developed in the third or fourth decade of life. The most frequent anatomic sites were the craniofacial bones, the femur, and the tibia. Twenty-three of the 83 cases were treated with local radiation. In fibrous dysplasia, any abrupt alteration in the clinical course, manifested by pain and swelling, raises the possibility of malignant degeneration.

Expression of Ia and monocyte-macrophage lineage antigens in giant cell tumor of bone and related lesions.

An immunohistochemical study of six giant cell tumors of bone and eight related lesions (aneurysmal bone cyst, fibrous histiocytoma, and giant cell tumor of tendon sheath) was performed using a panel of monoclonal antibodies directed to the Ia and monocyte-macrophage lineage antigens. In all types of lesion, osteoclastlike multinucleate giant cells were negative for both types of antigen, but a proportion of mononuclear cells gave positive reactions. While the possibility that these cells are reactive cannot be excluded, in giant cell tumor and malignant fibrous histiocytoma, their frequency and their morphologic similarity to the rest of the tissue suggest that they may be an intrinsic part of the neoplasm. This finding is consistent with the presumed fibrohistiocytic nature of these tumors.

Lysozyme and alpha 1-antitrypsin in giant-cell tumor of bone and in other lesions that contain giant cells.

We performed an immunohistochemical study of 24 giant-cell tumors of bone and 30 other lesions (fibrous histiocytoma, nonossifying fibroma, and giant-cell tumor of the tendon sheath) using lysozyme and alpha 1-antitrypsin as markers for histiocytic cells. The presence of histiocytic cells in giant-cell tumors of bone is confirmed by the finding of a positive reaction for alpha 1-antitrypsin in both multinucleate giant cells and mononuclear stromal cells in some cases. It is not clear whether the positive cells are to be regarded as neoplastic or reactive and alpha 1-antitrypsin is not considered as a diagnostically useful marker for giant-cell tumor of bone. In malignant fibrous histiocytoma, too, histiocytic cells could be identified by their positive reaction for alpha 1-antitrypsin; some of these cells had the morphologic features of tumor cells. Cells with a positive reaction for lysozyme were rarely found, except in giant-cell tumors of the tendon sheath.

The effect of discography on the canine intervertebral disc.

With increasing use of chemonucleolysis, interest and use of discography is at an all-time high. Various reports in past years have disagreed on the safety and efficacy of intradiscal injections of contrast mediums. This experimental study was devised to determine the effects of discography on the gross and histologic appearance of the lumbar intervertebral disc. Through a laparotomy approach, five lumbar discs in ten dogs were exposed. In each dog, one disc served as a control, another punctured with a needle, and the others injected with metrizamide, hypaque, or saline, At 2, 4, 6, 8, and 10 weeks postoperative, two dogs were killed at each time interval. Examination of the discs revealed no gross differences between any of the groups. The normal gross architecture of the concentric annulus and gelatinous nucleus was maintained in all specimens. This study found no evidence that discography results in gross or histologic damage to the intervertebral disc. It does not appear that discography will predispose a normal intervertebral disc to herniate. Discography alone appears to be a safe diagnostic procedure with no experimental evidence of any untoward gross or histologic effects.

Mechanisms of bone resorption in calcium-deficient rats.

A study of surface remodeling activity and osteocyte lacunar area was made in young and adult rats maintained on a low-calcium diet, to explore cellular mechanisms of bone resorption. The diet produced active remodeling of the endosteal part of the femoral cortex, with a decrease in the amount of bone present. Surface resorption, with numerous osteoclasts, was evident, but there was no evidence of osteocytic osteolysis in bone which, by tetracycline labeling, could be identified as existing at the commencement of the experimental period. Osteocyte lacunae in bone formed during the period of calcium deprivation were somewhat larger than lacunae in control animals, apparently because of interference with the formation or maturation of the perilacunar tissue.