Bizarre parosteal osteochondromatous proliferation. An unusual bone tumor

Bizarre parosteal osteochondromatous proliferation of bone is a rare, benign bone tumor. The authors discuss two cases involving the bones of the feet, and review clinical, radiographic, and histopathologic characteristics. Awareness of this lesion is essential as bizarre parosteal osteochondromatous proliferation of bone can be mistaken for a malignancy.     

Osteochondromalike parosteal osteosarcoma: a report of six cases of a new entity

OBJECTIVE: Our purpose was to describe a rare juxtacortical bone sarcoma with deceptively benign, osteochondromalike histologic characteristics. We present criteria by which this low-grade malignant neoplasm can be distinguished from other benign and malignant surface lesions of bone with particular emphasis on the imaging features. MATERIALS AND METHODS: Six cases of a low-grade, chondroossifying parosteal sarcoma of bone were reviewed. Patients included four males and two females 11 months to 66 years old. Histologic findings from initial tumors and from recurrent tumors were reviewed. Two musculoskeletal radiologists analyzed the imaging studies, which included plain films, CT scans, MR images, and a bone scan. RESULTS: Histologically, the lesions were characterized by a thin layer of proliferating, periosteally derived spindle cells overlying a thin, low-grade malignant cartilage cap that underwent calcification, neovascularization, and conversion into benign bone and marrow fat. These lesions were unique in that the malignant elements were only at their periphery. All six cases were initially misdiagnosed as benign lesions on pathologic evaluation. In each patient, imaging revealed a "pasted-on" ossified surface lesion with an intact underlying cortex and no medullary involvement. In three cases, recurrent tumors had histologic appearances consistent with conventional parosteal osteosarcoma. Dedifferentiation, metastases, and death occurred in one of these three cases. CONCLUSION: To our knowledge, this surface lesion of bone has not been specifically described. Whether this tumor constitutes a distinct entity or is a specialized variant of parosteal osteosarcoma is unclear. Precise radiologic-pathologic correlation is essential for appropriate diagnosis and management.     

Chondrosarcoma of the short tubular bones of the hands and feet

OBJECTIVE: To report 12 cases of chondrosarcoma in a rare location, the short tubular bones of the hands and feet, as well as 12 cases of enchondroma in similar locations, emphasizing the radiologic and histopathologic features. DESIGN AND PATIENTS: All relevant cases that had both histologic slides and radiographs available were taken from the files of one orthopedic referral hospital and the personal files of one of the authors. A similar number of enchondroma cases was selected at random from the files. RESULTS AND CONCLUSIONS: One malignancy arose in a background of enchondromatosis, with all the others being solitary lesions. A pathologic diagnosis of malignancy is often difficult in the absence of radiologic signs of malignancy (cortical destruction with or without soft tissue extension). However, three cases were unusual in that the initial radiograph demonstrated a benign appearance. Another group of three malignancies was surprisingly indolent biologically. The treatment of choice is ray resection (or more limited amputation in a lesion of the middle or distal phalanx).     

Leber''s neuroretinitis in a patient with serologic evidence of Bartonella elizabethae

Adamantinoma of the long bones is a rare skeletal tumor and its MR features have seldom been reported. It is difficult to distinguish from other bone lesions (such as osteofibrous dysplasia or osteosarcoma) by means of conventional radiography and CT. MR imaging, however, may be useful in differentiating adamantinoma from such lesions. With this presentation of a typical case, we hope to draw the attention of radiologists to this lesion and contribute information on its MR appearance.     

Multicentric giant cell tumor of bone

Giant cell tumor of bone accounts for 4% to 5% of primary bone tumors in the United States. Multicentric giant cell tumors occur in < 1% of all patients with giant cell tumors, and only 43 patients with multicentric giant cell tumor have been reported on in the literature. This series presents 3 additional cases of multicentric giant cell tumor, includes updated data for 2 patients previously reported on in the literature, and reviews 24 cases previously reported on in detail in the literature. The mechanism by which giant cell tumor involves multiple locations is not known. Multicentric giant cell tumor, in contrast to unifocal giant cell tumor, has a tendency to involve the hands, feet, and metaphysis/diaphysis of long bones and to occur in a slightly younger population. In 15 of the 29 patients reviewed, a second lesion did not develop for > 2 years after their initial presentation. Eighteen of those 29 patients had > 2 sites of tumor involvement, 1 of whom had 11 lesions. Two of the 5 patients in the authors' series presented with a spectrum of disease activity, with latent, active, and aggressive lesions present throughout the observation period.     

UVB-induced formation of (6-4) photoproducts in the rat corneal epithelium

A 12-year-old Maltese terrier was evaluated for progressive tetraparesis and neck pain. On radiographs, there was a periosteal reaction involving the fourth cervical vertebra. Myelographically, there was extradural compression of the spinal cord associated with the lesion. The dog was euthanized and necropsied. Histopathologic diagnosis was parosteal osteosarcoma of the vertebra.     

Matrix metalloproteinase-1 in cholesteatoma, middle ear granulations and deep meatal skin: a comparative analysis

The products of c-fos and c-jun proto-oncogenes form the heterodimeric complex AP-1 (activator protein 1), which play an important part in the control of bone cell proliferation and differentiation and in the development of bone tumours. We examined the expression of c-fos and c-jun in a series of 52 primary skeletal neoplasms, using an immunohistochemical method on formalin-fixed, paraffin-embedded sections. The expression of c-fos and c-jun was restricted to bone-forming lesions, while cartilaginous tumours were devoid of immunoreactivity. In benign osteoblastic lesions moderate c-fos and c-jun expression was found in 2 cases (18.1%). The highest levels of c-fos and c-jun expression were detected in high-grade central osteosarcomas (7 of 15 cases with moderate/diffuse expression) while 1 telangiectatic osteosarcoma, 2 low-grade central osteosarcomas, 1 low-grade periosteal osteosarcoma and 7 low-grade parosteal osteosarcomas were either negative or had low expression. The high-grade component of a dedifferentiated parosteal osteosarcoma showed diffuse immunoreactivity for both oncoproteins. Comparison of c-fos and c-jun expression by histological grade showed that high-grade osteosarcomas had a significantly higher expression of both oncoproteins than did low-grade osteosarcomas (P = 0.01, Fisher's exact test). Thus, c-fos and c-jun overexpression may be implicated in the development of high-grade osteosarcomas, but they appear to have little or no relevance for the development of low-grade osteosarcomas and cartilaginous skeletal neoplasms.     

The many faces of osteosarcoma

Osteosarcoma is the most common primary malignant tumor of bone in adolescents and young adults. It accounts for approximately 15% of all primary bone tumors confirmed at biopsy. There are numerous types of primary osteosarcoma, including intramedullary (high grade, telangiectatic, low grade, small cell, osteosarcomatosis, and gnathic), surface (intracortical, parosteal, periosteal, and high-grade surface), and extraskeletal. Osteosarcoma may also occur as a secondary lesion in association with underlying benign conditions. The identification of osteoid matrix formation and aggressive characteristics usually allows prospective radiologic diagnosis of osteosarcoma. As with all bone tumors, differential diagnosis is best assessed with radiographs, whereas staging is performed with computed tomography or magnetic resonance imaging. Understanding and recognition of the variable appearances of the different varieties of osteosarcoma allow improved patient assessment and are vital for optimal clinical management including diagnosis, biopsy, staging, treatment, and follow-up.     

Malignant lymphoma involving the patella

The majority of skeletal lesions affecting the patella are benign and include entities such as chondroblastoma, giant cell tumor, osteomyelitis, and gout. Malignant processes involving the patella are distinctly unusual. Isolated occurrences of plasmacytoma, osteosarcoma, hemangiosarcoma, and metastatic disease have been reported. Malignant lymphoma involving the patella is extremely uncommon, although lymphomatous infiltration of the skeletal system is not a rare event, especially with the histiocytic lymphoma. The most frequent radiologic manifestations of skeletal lymphoma include osteolytic lesions with ill-defined margins involving the metaphysis of the long bones of the lower extremities. Involvement of the short tubular and flat bones, as well as the axial skeleton, occurs less commonly. The prognosis for lymphoma involving the skeleton is poor.     

Macrodactyly of the feet and hands

We reviewed the records of 16 patients with true macrodactyly and analyzed the typical clinical features and methods of treatment. Fourteen feet were involved in 13 patients (one was bilaterally affected). Three hands were involved in three patients. Clinically, all lesions in the hands and lesions in 11 of 14 feet involved the preaxial side. There was multiple digit involvement in two hands and 11 feet. Progressive macrodactyly (10 feet and two hands) was more common than the static type (four feet and one hand). Proximal involvement of the sole or palm occurred in seven feet and one hand; all cases were of progressive macrodactyly. Enlargement of the metatarsals or the metacarpals was frequent (11 feet and two hands). The growth behavior and extent of bony involvement were similar in patients with hand involvement and those with foot involvement. Fourteen patients had additional clinodactyly, either medial or lateral. The toes of eight feet had angular deformities in the sagittal plane; most were angulated dorsally. Nine patients underwent surgery and two had repeated surgery. The reduction procedures included debulking, ray resection, toe resection, phalangeal resection, and phalangeal epiphysiodesis; the corrective procedures included wedge osteotomy, interdigitalization, and split thickness skin graft. Of the nine patients surgically treated, five had good results and four had fair results. Of the seven patients without surgical repair, three had fair results and four had poor results. Surgical debulking, phalangeal resection, ray resection, and phalangeal epiphysiodesis produced significant improvement in macrodactyly of the feet and hands. Toe resection was not as beneficial.     

Expression of c-met proto-oncogene product (c-MET) in benign and malignant bone tumors

The expression of c-met proto-oncogene product (c-MET) has been reported to be related to invasive growth or tumor stage in some tumors, but little is known concerning the significance of c-MET expression in bone tumors. With use of formalin-fixed, paraffin-embedded tissue specimens and polyclonal antibody for c-MET, we studied the expression of c-MET in 122 cases of malignant bone tumors (43 osteosarcomas, 24 chondrosarcomas, 21 malignant fibrous histiocytomas of bone, 16 Ewing's sarcoma versus primitive neuroectodermal tumors, 18 chordomas), 65 cases of benign tumors and tumor-like lesions (including 8 giant cell tumors of bone, 8 chondroblastomas, 12 enchondromas, 7 osteochondromas, 10 fibrous dysplasias), 7 cases of articular cartilaginous tissue, and 10 cases of fetal vertebral tissue consisting of foci of enchondral ossification and notochordal tissue. In malignant tumors, c-MET expression was most frequently detected in chordoma (94.4%), followed by chondrosarcoma (54.2%) and osteosarcoma (23.3%). Among the osteosarcoma specimens, c-MET expression was frequently detected in the chondroblastic subtype (66.7%), but the incidence was low in the cases with other subtypes of osteosarcoma. We found no significant correlation between the c-MET expression and the histologic grade of malignancy in either osteosarcoma or chondrosarcoma. c-MET expression was either rarely observed or completely negative in malignant fibrous histiocytomas of bone (4.8%) and primitive neuroectodermal tumors (0%). In benign tumors and tumor-like lesions, c-MET expression was frequently detected in cartilaginous tumors, such as chondroblastoma (62.5%), enchondroma (66.7%), and osteochondroma (71.4%), but no expression was observed in giant cell tumors of bone or any other benign tumors or tumor-like lesions. In normal tissue, c-MET expression was frequently detected in the articular cartilage (100%) and notochord (70.0%) specimens examined. We conclude that c-MET expression as frequent as that observed in the notochordal tissue, chordomas, articular cartilage, and cartilaginous tumors is related to the development of both normal tissue and chondroid tumors.     

Synchronous multifocal osteosarcoma: results in twelve patients treated with neoadjuvant chemotherapy and simultaneous resection of all involved bones

BACKGROUND: Multifocal osteosarcoma is a rare type of tumor which is always excluded from therapy trials and is therefore rarely investigated for prognosis and treatment. PATIENTS AND METHODS: Twelve patients with synchronous multifocal osteosarcoma underwent neoadjuvant chemotherapy and, when feasible, simultaneous resection of involved bones. RESULTS: Four patients were unsuitable for resection and died 5-13 months (average 9 months) later. In eight patients all lesions were resected simultaneously. Four patients are disease-free at 15, 20, 24, and 60 months (average 29 months), and four relapsed and died at 12, 24, 30 and 36 months (average 30.5 months). CONCLUSIONS: Chemotherapy associated with aggressive surgery may be useful. The histological response of different lesions in the same patient are strongly correlated, confirming that synchronous multifocal osteosarcoma is not originally multicentric but unicentric with bone metastases.     

Fibrous dysplasia of the maxillofacial bones. Clinical considerations

OBJECTIVE: After a wide survey of the literature, the results of a clinical-statistic study carried out on twelve cases of maxillo-facial bones fibrous dysplasia, diagnosed and treated at the Oral and Maxillo-Facial Surgery Department of the II University of Naples, are reported. EXPERIMENTAL ASSAY: Retrospective study. MATERIALS AND METHODS: All the patients examined showed fibro-osseus lesions involving the mandible in eight cases, the maxilla in three cases and the frontal bone in one case. Seven patients were females and five males, aged between nine and seventy-two years. The surgical treatment was carried out on eleven patients: four cases were treated by complete surgical excision of the fibro-osseous lesions and seven cases by a conservative removal of the portion of the lesion contributing to the bone deformity. RESULTS AND CONCLUSIONS: All cases examined involved maxillo-facial skeleton structures as a sole localization, confirming that the polyostotic forms are more infrequent than the maxillary monostotic ones. The distribution of the cases according to age classes and lesion localization showed a higher incidence of fibrous dysplasia in the third decade of life and a clear predilection for the mandible. The observation of active lesions in old age shows that the disease may evolve also after the growth. The cases treated by radical excision of the lesions have not been followed from relapse; on the contrary three of the seven cases treated by conservative excision relapsed after a few years.     

Disappearance of soft tissue and the disarticulation of human remains from aqueous environments

Human remains recovered from aquatic environments were scored for regional presence of soft tissue, exposure of bone, and loss of body parts to determine the general pattern of soft tissue loss and loss of body parts. Regions scored were: the cranium, mandible, neck, hands, forearms, upper arms, feet, legs, pelvic girdle, and trunk. Initial disappearance of soft tissue, resulting in exposure of underlying bones, occurred in areas thinly overlain by soft tissue beginning with the head, hands, and anterior lower legs. Disappearance of body parts followed the general sequence: bones of the hands and wrists, bones of the feet and ankles, and the mandible and cranium. The lower legs, forearms, and upper arms are the next units to separate from the body. Known postmortem intervals for remains analyzed ranged from weeks to years and could not reliably be estimated based on the condition of the body at the time of recovery. As parts drop away from a floating carcass in large or current-driven bodies of water, they are often separated from the major body unit. This complicates recovery. Knowledge of disarticulation sequences allows more informed assessment of skeletal element recoveries to be expected and assists in the interpretation of artifacts and events produced by different disarticulating environments.     

Chondromyxoid fibroma-like osteosarcoma: a distinct variant of low-grade osteosarcoma

Chondromyxoid fibroma-like osteosarcoma is a recently described, extremely rare subtype of low-grade osteosarcoma. Two such cases were encountered among 102 cases of osteosarcoma seen in the Prince of Wales Hospital, Hong Kong, between 1984 and 1994. The first patient, a 39-year-old woman, presented with a mass in her right maxilla which was resected and mistaken as a myxoma. The tumour recurred locally four years later and she now has extensive local recurrent disease six years after initial presentation and is amenable to support treatment only. The second patient, a 28-year-old man, had a pelvic tumour which recurred in the form of a polypoid left atrial tumour and pulmonary nodules six years after operation. The left atrial tumour recurred one year after operation, and led to sudden death of the patient seven years after initial presentation. Radiologically, the tumours in both cases appeared as expansile osteolytic lesions with erosion of adjacent bone and infiltration into soft tissue. Histologically, they consisted of lobules of spindle, stellate or polygonal tumour cells showing mitotic activity and with moderate nuclear pleomorphism and hyperchromatism, set in a highly myxoid stroma superficially mimicking chondromyxoid fibroma. The histological hallmark was the direct production of osteoid by tumour cells. Chondromyxoid fibroma-like osteosarcoma merits recognition as a distinct variant of low-grade osteosarcoma for which early appropriate surgery is indicated.     

Postradiation sarcoma of bone: review of 78 Mayo Clinic cases

Postradiation sarcoma of bone is an uncommon but serious sequela of radiation therapy. Seventy-eight Mayo Clinic patients have been treated for sarcomas arising in irradiated bones. They received their initial radiotherapy for a wide variety of nonneoplastic and neoplastic conditions, both benign and malignant. Thirty-five sarcomas arose in bone that was normal at the time of radiotherapy, and 43 arose in irradiated preexisting osseous lesions. The latent period between radiotherapy and diagnosis of sarcoma averaged 14.3 years. Ninety percent of the postradiation sarcomas were either osteosarcomas or fibrosarcomas; chondrosarcoma, malignant (fibrous) histiocytoma, malignant lymphoma, Ewing's tumor, and metastasizing chondroblastoma also occurred. Prompt radical surgery, when feasible, is usually the treatment of choice for the sarcoma. About 30% of patients with sarcomas of the extremities or craniofacial bones survived 5 years without recurrence; there were no disease-free survivors among patients with tumors of the vertebral column, pelvis, or shoulder girdle. The low risk of sarcoma following radiotherapy for the treatment of cancer should not be a contraindication to its use in these patients; however, radiation therapy for benign bone tumors should be reserved for lesions that are not amenable to surgical treatment. An unusual case is also reported herein in which a fibrosarcoma was discovered in the humerus of a patient who had received radiotherapy 55 years previously for a verified osteosarcoma in the same site.     

Co-amplification and overexpression of CDK4, SAS and MDM2 occurs frequently in human parosteal osteosarcomas

Amplification of genes in the 12q13-15 region occurs frequently in several malignancies including osteosarcoma. The products of these amplified genes are thought to provide cancer cells with a selective growth advantage; however, the specific gene(s) driving this amplicon is unknown. We have previously shown that the SAS gene is amplified in most parosteal osteosarcomas. In this study we analysed additional putative growth regulatory genes in this chromosomal region in 24 primary osteosarcoma specimens. CDK4 and SAS were coamplified in 6/6 parosteal tumors, and MDM2 was also amplified in 4/5 parosteal cases. In comparison, amplification occurred in only 2/16 classical intramedullary osteosarcomas and involved the SAS gene. Each amplified gene had a correspondingly elevated mRNA level. Four high grade intramedullary tumors had elevated mRNA expression of SAS, but did not exhibit gene amplification. Gene amplification/overexpression was not associated with metastatic disease and did not change markedly with tumor progression, as evidenced by analysis of sequential tumor specimens from eight patients. Three other genes in the 12q13-15 region (CDK2, WNT1 and WNT10b) were not amplified in any of the tumors. The different patterns of gene amplification and overexpression of CDK4, SAS and MDM2 in parosteal and intramedullary osteosarcomas may help explain the disparity in the biological behaviour of these two types of osteosarcoma.     

Clear cell tumors of bone

Except for clear cell carcinomas that metastasize to bone, with renal cell carcinoma being the principal representative of that group, clear cell osseous neoplasms are rare. The only distinct nosologic entity in this category that is primary in the bone is the clear cell chondrosarcoma (CCCS). This lesion, which is most often seen in the proximal femur or humerus, affects males more often than females and has a peak incidence during the third and fourth decades of life. Radiologic images of CCCS show a well-circumscribed, often calcified lytic lesion that may expand the bone, but only uncommonly breaches the cortex. Clear cell elements in CCCS are accompanied by "conventional" foci of chondrosarcoma in less than 50% of cases; noncartilaginous "secondary features," including areas of osteogenesis, osteoclast-like giant cells, and zones resembling aneurysmal bone cyst or giant cell tumor of bone, may be apparent as well. CCCS is a relatively indolent malignancy; roughly 25% of patients experience local recurrences of their tumors or suffer metastasis, but tumor-related death is uncommon, particularly when the lesion has been completely resected en bloc. Sporadic examples of other tumors in bone also may be focally or entirely composed of clear cells. These include osteosarcoma, chondroblastoma, chordoma, adamantinoma, Ewing's sarcoma, and primitive neuroectodermal tumor. The last two of these lesions represent the most common primary clear cell bone tumors in children, whereas metastatic renal clear cell sarcoma is the most frequent metastatic pediatric tumor in this category.     

多中心骨巨细胞瘤9例报道与文献分析

Objective: The aim of this study was to investigate the clinical, radiographic and histiopathologic features of multicentric giant cell tumor of bone. Methods: All the clinical data of twenty tumors in nine patients of multicentric giant cell tumor that underwent surgical treatment in our department from 1990 to 2010 were retrospectively reviewed, which included three males and six females. The patients ranged from 15 to 45 years at diagnosis, with an average age of 22.3 years. Three of the patients were younger than twenty years of age. Most tumors arose in long bones, especially around the knee. Radiographically, the tumors in long bones usually manifested as expansive lytic lesions involving the metaphysis and extending into the epiphysis. Three tumors in three patients were confined to the metaphysis, and one tumor exhibited bone-forming lesions. All tumors were treated with curettage or resection. Results: The typical "giant cell" could be found in the oncologic examination in all cases. In some areas, such as the fibrohistiocytic regions, reactive bone forming and aneurysmal bone cyst-like changes could be found. Follow-up averaged 3.5 years, ranging from 6 months to 12 years. There was a recurrence of three tumors, and one patient died of pulmonary metastasis. Conclusion: Multicentric giant cell tumor occur often in younger patients than do solitary giant cell tumor. They are frequently present around the knee, and confined to the metaphysis. Each tumor arose independently, rather than being in multiple sites of metastatic lesion that develop from a single tumor. The risk of recurrence depends on the type of surgery that is performed.