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.

Assessment of argyrophilic nucleolar organizer region quantification in benign and malignant bone tumors.

Quantification of argyrophilic nucleolar organizer regions has been proposed as a technique that may aid in diagnosing and predicting the biologic behavior of a variety of neoplasms. A 1-step silver staining technique was used to identify and quantify argyrophilic nuclear organizer regions in a series of 96 bone tumor specimens. Malignant bone tumors had a higher mean argyrophilic nuclear organizer region count (3.

Giant cell tumor of the capitate. A case report.

Giant cell tumors in the small bones of the hand are unusual, particularly in the carpus. A 28-year-old woman developed a giant cell tumor in the capitate. After biopsy, she was treated with complete excision of the capitate with no reconstruction.

Characterization of the pseudocapsule of soft-tissue sarcomas. An experimental study in rats.

The effect of preoperative radiation therapy on the pseudocapsule of experimental rat soft-tissue sarcomas has not been histologically evaluated in a controlled study. The irradiated animal showed marked thickening of the capsular structure surrounding the sarcoma. Everywhere morphologically distinct from the tumor, there was no evidence of tumor invasion into or through this capsular structure.

Osteoid osteoma and osteoblastoma.

In conclusion, while similar histologically, osteoid osteoma and osteoblastoma have the potential of being significantly different clinically. Osteoid osteoma tends to be a problem of pain and not of great oncologic significance. Osteoblastoma, on the other hand, has the potential for local bone destruction and aggressiveness as well as the rare occurrence of metastases.

Diagnostic difficulties in skeletal pathology.

In this review are discussed a small group of bone tumors that present the greatest and sometimes unresolved problems in diagnosis, not only for the clinician but also for the pathologist, even with full knowledge of the clinical and roentgenologic presentation. The following neoplastic lesions are described in detail: cartilage-forming tumors, bone-forming tumors (with special emphasis on aggressive or malignant osteoblastoma), and round-cell tumors of bone. This last group presents a special challenge to the pathologist even after histopathologic examination.

Adamantinoma of the tibia masked by fibrous dysplasia. Report of three cases.

Three cases of adamantinoma of the tibia associated with and mimicking fibrous dysplasia or osteofibrous dysplasia are reported in children aged three, nine, and 16 years. The roentgenographic features were typical of intracortical fibrous dysplasia (osteofibrous dysplasia). These entities are not two distinct diseases, but rather are different histologic expressions of essentially the same process, which varies depending on location (predominantly intracortical or medullary) and age.

Osteosarcomas arising on the surfaces of long bones.

Malignant bone-forming tumors that arise from the surfaces of long bones are far less common than those that arise from within bone. These surface osteosarcomas are clinically and radiographically similar, yet histologically they are quite distinct. In reviewing the literature, we classified the tumors according to three subgroups: parosteal (juxtacortical) osteosarcoma, periosteal osteosarcoma, and high-grade surface osteosarcoma.

Metastases of carcinoma in the pagetic bone. A report of two cases.

Two men, aged 68 and 77 years, had metastases of carcinoma in pagetic bones. These cases were initially diagnosed clinically as Paget's sarcoma. Roentgenograms, scintigrams, and bone puncture biopsy specimens (BPBs) of the right scapula and the sacrum, respectively, showed only Paget's disease.

Chondromyxoid fibroma: report of three cases with predominant cortical involvement.

The clinicoradiologic and pathologic aspects of three cases of chondromyxoid fibroma of small size and predominant cortical location are reported. Because of these unusual features, the possibility of chondromyxoid fibroma was not considered on the basis of the radiographic pattern. The diagnosis was made after pathologic examination of the tissue, obtained in two cases via needle biopsy, which led to the appropriate treatment, en bloc excision.

Soft-tissue masses: histologic basis for decreased signal (short T2) on T2-weighted MR images.

Most soft-tissue masses and tumors of various etiologies and histologies have high signal intensity on T2-weighted pulse sequences (long T2). Of 47 soft-tissue masses, seven had a low signal (short T2) on T2-weighted pulse sequences. All seven masses were tumors, and histologic review showed that their composition differed from that of the other 40 lesions with a long T2 in that the seven masses were relatively acellular and had more collagen.

Tissue-typing in human massive allografts of frozen bone.

The cases of twenty-six patients who received a massive allotransplant of frozen bone, with a known degree of histocompatibility between the donor and the recipient, were studied. Twenty-two patients were followed for more than two years (range, twenty-four to ninety-two months). Twenty-three biopsies were performed in sixteen patients from nine to seventy-eight months after transplantation.

Spontaneous fractures of uninvolved bones in patients with Paget's disease during unduly prolonged treatment with disodium etidronate (EHDP).

Three patients with Paget's disease of bone were treated by disodium etidronate (EHDP) without interruption during periods of 18 to 30 months. In one case the daily dose was also unduly high (approximately equal to 18 mg/kg/day). A moderate to conspicuous diminution of the renal function was observed in all cases.

Virus-like intranuclear inclusions in giant cell tumor of bone.

An ultrastructural study of 13 cases of typical giant cell tumor of bone (GCT) revealed the presence of virus-like intranuclear inclusions (INI), morphologically identical to those reported in Paget's disease of bone. In two giant cells of two different patients, INI were found only after careful survey of a great number of cells. This finding, coupled with the scarcity of GCT with similar inclusions reported in the literature, reveals the extreme rarity of this finding and leaves open to discussion the specificity of these INI even in Paget's disease, as well as the possible etiological significance in giant cell tumor of bone.

Current trends in the diagnosis and treatment of malignant bone tumors.

After a review of the potential of current methods of investigation and of the slightly modified WHO bone tumor classification, the following neoplastic lesions, the diagnosis and treatment of which still present some unsolved problems, are described in detail: giant cell tumor (osteoclastoma); osteosarcoma, with special reference to malignant osteoblastoma; periosteal osteosarcoma and its disputed relation with or supposed identity to juxtacortical chondrosarcoma; Ewing's sarcoma; and malignant fibrous histiocytoma.

Sarcoma complicating Paget's disease of bone. A clinicopathological study of 62 cases.

Out of 21 900 cases filed at the Latin-American Registry of Bone Pathology between April 1940 and July 1981, there were 987 with Paget's disease (4.51 per cent); 62 of these (6.28 per cent) were complicated by sarcoma and two were associated with giant-cell tumours of bone (osteoclastoma) without signs of malignancy.

Microspectrophotometric quantitation of DNA in bone tumors with giant cells (osteoclastoma, osteosarcoma and chondroblastoma).

A microspectrophotometric study of DNA content was carried out on cells from three types of bone tumor--osteoclastoma, chondroblastoma, and osteosarcoma--in all of which the formation of multinucleated giant cells occurs. Giant cells of osteoclastic type were present in all the tumors, with contents of DNA which were constant, uniform and diploid in character for each nucleus individually considered. Since there were no nuclei with reduced or increased content of DNA, mitotic proliferation or gemmation can be excluded.

Intracortical haemangioma simulating osteoid osteoma.

A case of intracortical haemangioma in the tibial diaphysis is reported. The radiological and macroscopic features were identical with osteoid osteoma. In view of this similarity, haemangiomata, despite their rarity at this site, must be considered in the differential diagnosis of osteoid osteoma.

Juxta-articular bone cysts (intra-osseous ganglia): a clinicopathological study of eighty-eight cases.

The clinical, radiographic and pathological features of eighty-eight cases of histologically verified intra-osseous ganglia in eighty-three patients are described. All were located in the subchondral bone adjacent to a joint and most frequently involved the hip, the ankle (medial malleolus), the knee and the carpal bones. Forty-seven of the eighty-three patients were male and all the patients were between fourteen and seventy-three years of age, with an average age of forty-one years.