Ewing's sarcoma of bone tumor cells produces MCSF that stimulates monocyte proliferation in a novel mouse model of Ewing's sarcoma of bone.

Ewing's sarcoma of bone is a primary childhood malignancy of bone that is treated with X-radiation therapy in combination with surgical excision and chemotherapy. To better study Ewing's sarcoma of bone we developed a novel model of primary Ewing's sarcoma of bone and then treated animals with X-radiation therapy. We identified that uncontrolled tumor resulted in lytic bone destruction while X-radiation therapy decreased lytic bone destruction and increased limb-length asymmetry, a common, crippling complication of X-radiation therapy. Osteoclasts were indentified adjacent to the tumor, however, we were unable to detect RANK-ligand in the Ewing's tumor cells in vitro, which lead us to investigate alternate mechanisms for osteoclast formation. Ewing's sarcoma tumor cells and archival Ewing's sarcoma of bone tumor biopsy samples were shown to express MCSF, which could promote osteoclast formation. Increased monocyte numbers were detected in peripheral blood and spleen in animals with untreated Ewing's sarcoma tumor while monocyte number in animals treated with x-radiation had normal numbers of monocytes. Our data suggest that our Ewing's sarcoma of bone model will be useful in the study Ewing's sarcoma tumor progression in parallel with the effects of chemotherapy and X-radiation therapy.

Heterogeneous expression of melanoma antigen (hMAGE) mRNA in mesenchymal neoplasia.

Recommendations have been advanced recently for the use of cancer/testis (CT) immunotherapy against sarcomas. CT antigens are encoded by cancer-germline genes (e.g., hMAGE family) that are expressed in tumors and male germline cells but typically not in normal tissues. At present, little information is available regarding CT expression in mesenchymal neoplasms, and it remains uncertain whether CT immunotherapy will serve as a viable alternative or adjunct to current sarcoma therapies involving resection, followed by adjuvant radiotherapy and/or chemotherapy. In this study, hMAGEA2, hMAGEA3, hMAGEA4, and hMAGEC1 mRNA content in 21 benign mesenchymal tumors (representing seven histotypes) and 28 primary sarcomas (10 histotypes) was inventoried using real-time-PCR and then compared against hMAGE mRNA expression in non-sarcomatous malignancies, three cell lines, and muscle. hMAGEA2, hMAGEA3, and hMAGEC1 transcripts were infrequent in mesenchymal tissues in general, whereas hMAGEA4 mRNA was present in 84% of all mesenchymal tumors, 100% of non-sarcomatous tumors, all three cell lines, and in four of five muscle samples. Although hMAGEA4 mRNA was detected in four of five muscle preparations, there was no indication that the mRNA was translated into protein. The presence of hMAGEA4 mRNA in muscle, plus the inconsistent and infrequent occurrence of hMAGEA2, hMAGEA3, and hMAGEC1 mRNA within and among mesenchymal tumor histotypes, makes these four hMAGE antigens unlikely candidates for sarcoma-specific immunotherapy.

Effects of radiation therapy on chondrocytes in vitro.

The negative irradiation complications of growth loss leading to limb length asymmetry and pathological fracture incurred following radiation therapy in pediatric patients has led to a renewed interest in understanding the specific effects of irradiation on the growth plate and the surrounding bone. In the present report, we examined the radiation therapy effects on primary rat growth cartilage chondrocytes in order to determine the chondrocyte radiosensitivity relative to other bone cell constituents and tumor cells, the postirradiation temporal progression of radiation-induced alterations in chondrocyte function, and the time course for the functional restoration of chondrocyte pathways that drive the eventual recovery in growth function. We employed an in vitro primary rat costochondral growth cartilage cell culture model system to evaluate the radiation therapy effects on proliferative chondrocytes using serial radiation doses (0-20 Gy) that are well within the clinically relevant range. Following irradiation, all of the following occurred in a dose-dependent manner: proliferation decreased, cytotoxicity increased, several markers of apoptosis increased, markers of radiation-induced cellular differentiation increased, and cell synthetic activity was disturbed. Alterations in proliferation, cell death, and induction of apoptosis are likely due to a transient radiation-induced derangement of the parathyroid hormone-related protein-Indian hedgehog proliferation-maturation pathway. Alterations in cellular differentiation and cell synthetic activity are novel observations for chondrocytes. Further, these results correspond very well to our previous work in an in vivo Sprague-Dawley rat model, making this model particularly relevant to researching the radiation therapy effects on longitudinal growth.

Density and structural changes in the bone of growing rats after weekly alendronate administration with and without a methotrexate challenge.

Alendronate (ALN) and other bisphosphonates have been used successfully in pediatric patients with osteopenia secondary to connective tissue diseases. Loss of growth in height has not been reported, but concerns remain regarding the effect of these potent antiresorptive agents when used in children and adolescents. High-dose methotrexate (MTX) and other chemotherapy drugs have been implicated in osteoporosis and a high fracture incidence in survivors of childhood cancers and are also associated with osteopenia in adult animals. The effect of high dose MTX on bone density during rapid skeletal growth, however, has not been widely studied, nor has the potentially therapeutic effect of bisphosphonates in this setting. We examined the effects of ALN and MTX administration, alone and in combination, on bone density, morphology, mechanical strength, and longitudinal growth in normal growing rats. Sprague-Dawley rats were given ALN once weekly (0.3 mg/kg) from 5 to 11 weeks of age, with and without a course of methotrexate (MTX) given daily in weeks 1 and 3 (0.75 mg/kg/day). Twenty-four animals were randomly divided into four groups: Control (vehicle), ALN alone, ALN + MTX, and MTX alone. After 6 weeks, the femora, tibiae, and lumbar spine were studied by dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, mechanical strength testing, microradiography, light microscopy, and by determination of ash weights and bone lengths. ALN treatment increased bone mineral density (BMD) by 23% to 68%. The largest increases in the femur occurred in the distal third where endochondral bone growth was greatest and included large increases in trabecular bone and total cross-sectional area. ALN + MTX produced similar effects to ALN alone. MTX only reduced BMD by 8% in the vertebrae, but not significantly at other sites. MTX also led to femoral length reductions of 2.9%. The small reductions in BMD due to MTX were overwhelmed by the increases due to ALN, whereas the length loss was unaffected. Transverse density banding corresponding to weekly ALN administrations were clearly evident radiographically throughout the growing skeleton, likely due to decreased resorption and possibly increased mineralization in the bands. ALN or ALN + MTX treatment also led to increases in mechanical strength in the femora. Although MTX administration during growth leads to some BMD reduction, ALN given with MTX eliminates this reduction and in fact bone density and strength increase above control levels.

Predictive value of gadolinium enhancement in differentiating ALT/WD liposarcomas from benign fatty tumors.

OBJECTIVE: To determine the predictive value of gadolinium enhancement on MRI in differentiating atypical lipomatous tumor (ALT)/well-differentiated (WD) liposarcoma from benign fatty tumors. DESIGN: All histologically proven fatty tumors with preoperative gadolinium-enhanced MRI were reviewed. Only those tumors with predominantly fatty signal were included. Sensitivity, specificity, and positive and negative predictive values for both gadolinium enhancement and biopsy as predictors for the final diagnosis of ALT/WD liposarcoma were calculated. PATIENTS: From 129 patients evaluated for fatty tumors between 1994 and 2002, the patient population was narrowed to 32 excised fatty tumors with preoperative gadolinium-enhanced MRI. RESULTS: As a predictor of ALT/WD liposarcoma, the presence of gadolinium enhancement showed 100% sensitivity, 71% specificity, 53% positive predictive value and 100% negative predictive value. Needle or incisional biopsy yielded 57% sensitivity, 100% specificity, 100% positive predictive value and 63% negative predictive value for a diagnosis of ALT/WD liposarcoma. CONCLUSIONS: Gadolinium enhancement of a homogeneous fatty soft tissue tumor is a sensitive screening tool to determine possible diagnosis of ALT/WD liposarcoma. Biopsy, on the other hand, is specific but insensitive.

Novel radioprotectant drugs for sparing radiation-induced damage to the physis.

PURPOSE: To determine if pentoxifylline, interleukin 1alpha, selenium and misoprostol can minimize damage to physeal longitudinal growth during single radiation dose exposure in an animal model. MATERIALS AND METHODS: Eighty-seven weanling Sprague-Dawley rats were randomized into 15 drug/dose groups. All groups received a single 17.5-Gy gamma-irradiation exposure to the right knee, the left limb serving as an internal control. Pentoxifylline was injected 30 min before exposure, sodium selenite and interleukin 1alpha 24 h before exposure and misoprostol 2 h before exposure. Positive controls received 17.5 Gy. At 6 weeks, animals were sacrificed, the hind limb lengths were measured and detailed histomorphometric analysis was performed. RESULTS: Statistically significant reductions (p < or = 0.03) in mean limb length discrepancy compared with irradiation alone were seen following administration of pentoxifylline (50 mg kg(-1)), interleukin 1alpha (15 mcg kg(-1)), selenium (5 mg kg(-1)) and misoprostol (20 mg kg(-1)). Histomorphometric endpoints and growth rate remained altered at 6 weeks despite treatment, but length discrepancy reduction was highly correlated with the appearance of regenerative clones. CONCLUSIONS: Each drug reduced the amount of anticipated growth arrest in the animal model and some compared favourably in magnitude with that previously demonstrated for the established radioprotectant drug amifostine. Restoration of growth appears related to appearance of regenerative clones.

Inheritance of osteosarcoma and Paget's disease of bone: a familial loss of heterozygosity study.

Pagetoid osteosarcoma is a complication of Paget's disease of bone. Sarcomatous transformation is most often seen in severe, long-standing Paget's disease. Familial clustering of Paget's disease has been described with apparent autosomal dominant inheritance with high penetrance by the sixth decade. Although definitive proof of the specific gene involved remains elusive, some researchers have shown loss of heterozygosity in a region of chromosome 18q in a relatively high percentage of studied patients affected with either Paget's disease alone, in Pagetoid osteosarcoma, and in uncomplicated osteosarcoma. Our patient was diagnosed with Pagetoid osteosarcoma and had a first-degree relative with history of the same. We hypothesized that our patient's tumor samples might contain a similar genetic abnormality. Our analysis of several polymorphic markers from the chromosome 18q21-22 region showed loss of maternally inherited alleles throughout the region. This finding is similar to those described previously and provides further evidence of a susceptibility region relating to this disease. This report describes a father and son, their young ages at diagnosis of Pagetoid sarcoma, the identical sites of disease involvement, and a loss of heterozygosity study illustrating the inheritance of the presumed defective gene.

Distinction of well-differentiated liposarcoma from lipoma in two patients with multiple well-differentiated fatty masses.

This case report describes the features of gadolinium-enhanced MRI in well-differentiated liposarcoma with histologic correlation and addresses the usefulness of this imaging technique in distinguishing well-differentiated liposarcoma from lipoma. Gadolinium-enhanced MRI revealed significantly enhanced signal in well-differentiated liposarcoma in a background of multiple well-differentiated benign fatty masses by showing the increased vascularity in the septa of well-differentiated liposarcoma. Although such signal enhancement can be seen in some types of benign lipomatous tumors with increased blood vessels, this technique is helpful in selection of biopsy site, especially in a clinical setting of multiple fatty masses.

Diagnosis of chondroid lipoma by fine-needle aspiration biopsy.

Chondroid lipoma is a rare, recently described soft tissue tumor that mimics extraskeletal chondrosarcoma and myxoid liposarcoma. Reports regarding its cytologic and radiological features are sparse. In this report, we describe the cytologic features of this unusual tumor, which include mixed mature lipocytes and lipoblast-like cells embedded in chondromyxoid matrix. We also describe the "target sign appearance" of this tumor in magnetic resonance imaging studies, resembling a neurogenic tumor. More importantly, we demonstrate that a definitive diagnosis of this unusual tumor can be made by fine-needle aspiration biopsy. The usefulness of cell block in fine-needle aspiration biopsy diagnosis of soft tissue tumors is emphasized.

Benign tumefactive soft tissue extension from Paget's disease of bone simulating malignancy.

Osteosarcoma is a frequently fatal complication of Paget's disease of bone typically manifesting radiographically as a lytic lesion with soft tissue extension. A clinically worrisome, but benign manifestation of Paget's disease simulating malignancy because of an extraosseous mass is reported.

Amifostine before fractionated irradiation protects bone growth in rats better than fractionation alone.

The aim of this study was to determine the independent and combined effects of 100 mg/kg and 200 mg/kg doses of the radioprotectant amifostine and radiotherapy dose fractionation in preserving the integrity of or minimizing damage to the physis during high-dose radiation exposure in an animal model. Thirty-six weanling four-week-old male Sprague-Dawley rats were randomized into six study groups of six animals each. The distal femur and proximal tibia in the right leg of each animal was exposed to X-irradiation, with the contralateral left leg serving as the nonirradiated control. Three groups received a single 25 Gy radiotherapy dose: one group alone, a second group preceded by 100 mg/kg amifostine, and a third preceded by 200 mg/kg amifostine. Three groups received a total of 25 Gy in three equal fractions: one group alone, a second group preceded by 100 mg/kg amifostine, and a third preceded by 200 mg/kg amifostine. Fractionation of the 25 Gy radiation dose reduced the mean percent overall limb growth loss to 44.8%, a statistically significant reduction compared to a mean 58.8% reduced growth with the single 25 Gy dose. Addition of amifostine at 100 and 200 mg/kg before each of the three fractions of radiotherapy further decreased the mean percent overall limb growth loss to 35.2% and 28.5%, respectively, both statistically significant reductions beyond that achieved by fractionation alone.

Bone metastases from squamous cell carcinoma of the head and neck.

BACKGROUND AND OBJECTIVES: Carcinoma of the head and neck is an uncommon primary source of bone metastases. The increasing duration of survival of these patients, however, increases the probability of late bone involvement. The objective was to identify the frequency, clinical presentation, and clinical course of metastatic disease to bone from head and neck primaries. METHODS: A retrospective review was accomplished of the radiographs and nuclear medicine studies for 363 cases of squamous cell carcinoma of the head and neck for whom radiologic studies had been performed. For those with identified bone involvement, a chart review was performed to identify clinical presentation, disease course, and outcome. RESULTS: Only approximately 1% of these patients had clinically demonstrable bone metastases. Eight sites of bone involvement were identified in five patients, including three pelvic, two femoral, and one each humeral, rib, and thoracic spine lesions. All lesions were purely lytic with moth-eaten or permeative borders. Time from primary tumor diagnosis to identification of metastatic disease ranged from being present at diagnosis to a maximum 3.5 years later. Time from identification of metastatic disease to patient death was no greater than 8 months. CONCLUSIONS: Despite the increasing overall survival of patients with these carcinomas, distant bone metastases are infrequent, but should be considered a possibility in any patient with a concurrent or past diagnosis of head and neck carcinoma. The very short time from discovery of bone dissemination to death in most of these patients should be taken into consideration when contemplating operative intervention.

Management of metastatic disease to soft tissue.

Metastases to soft tissue are rare clinical problems. Most metastases are caused by carcinomatous deposits in the skeletal muscle, with lung carcinoma being the most common primary cause. Pain is more commonly observed in association with metastatic soft tissue masses than for soft tissue sarcomas. Treatment should be individualized, but for most carcinomas, initial radiotherapy treatment is recommended. Prognosis varies with the underlying disease, but for the typical patient with a metastatic carcinoma, mean survival duration is approximately 6 months.

Distant soft tissue metastases: a series of 30 new patients and 91 cases from the literature.

BACKGROUND: Thirty patients with soft-tissue metastases were reviewed retrospectively and compared with 91 cases previously reported. Soft tissue metastases were most commonly presented to the musculoskeletal oncologist as a painful mass in patients with no history of cancer. In this setting, lung carcinoma was the most frequent primary source. The purpose of this article is to report the largest single series of distant soft-tissue metastases and to compare the findings with those of the literature. METHODS: Thirty consecutive patients were referred to musculoskeletal oncologists. Their cases were reviewed retrospectively for comparison with 91 cases from the clinical literature. RESULTS: The most common clinical presentation of the soft-tissue mass was as the presenting symptom of previously undiagnosed cancer or concurrent with the primary source of cancer. A minority of cases were discovered in the setting of widespread metastases. Twenty-one new patients had carcinomas, 6 sarcomas, and 1 each multiple myeloma, lymphoma, and melanoma. Lung carcinoma was the most common primary source. The most common presenting symptom was that of a painful mass. Skeletal muscle of the thigh was the most common site. Radiological features were not specific. Soft tissue sarcoma was a common clinical misdiagnosis. Twenty-one new patients were dead of disease at a mean 5.4 months (range 1-19 months) after diagnosis of the metastasis: this percentage was similar to that reported in the literature. CONCLUSIONS: In this musculoskeletal oncology referral-based clinical series, soft tissue metastases most commonly occur in patients with a painful soft tissue mass and no history of cancer. Lung is the most frequent primary source. Treatment should be individualized according to the underlying disease and its prognosis.

Surgical treatment for metastatic disease of the pelvis and the proximal end of the femur.

Advances in the treatment of invasive cancers continue to improve the longevity of patients who have these diseases; thus, the care of patients who have bone metastases is an issue of the utmost importance to the orthopaedic surgeon. In terms of maintaining the ability to walk, no site of potential metastatic involvement is more crucial than the proximal end of the femur and the acetabulum. Advances in femoral and acetabular implants, imaging modalities, and operative techniques now allow reconstruction of even the most complex acetabular and proximal femoral defects. However, the orthopaedic surgeon must recognize the need to approach management of these patients from a multidisciplinary perspective. The oncologist, radiotherapist, rehabilitation medicine specialist, radiologist, and pathologist each have a role to play. Only through cooperation among all members of the team will a patient who has metastatic disease or a myeloma be given the best possible care.

Sparing of radiation-induced damage to the physis: fractionation alone compared to amifostine pretreatment.

PURPOSE: The purpose of this study was to determine the relative benefits of sparing longitudinal bone growth by fractionation alone compared to pretreatment with amifostine, a chemical that provides differential radioprotection of normal tissues. METHODS AND MATERIALS: Twenty-four weanling 4-week-old male Sprague-Dawley rats were randomized into 2 overall treatment groups: fractionation alone (n = 12) and amifostine pretreatment (n = 12). The distal femur and proximal tibia in the right leg of each animal were exposed to a therapeutic X-irradiation dose (17.5 Gy total in 3 or 5 fractions) with the contralateral left leg as control. In 12 of the animals, amifostine (100 mg/kg) was administered intraperitoneally 20 min before radiation exposure. Six weeks later, growth was calculated based upon measurement of the bone lengths. RESULTS: Fractionated radiation resulted in a mean percent overall limb growth loss of 21. 1 +/- 7.0%. The addition of amifostine brought the mean percent overall limb growth loss to 16.3% +/- 4.6%, which showed a strong trend toward significance compared to fractionation alone (p = 0. 061). The addition of radioprotection with amifostine to 5 fractions irradiation significantly reduced the femoral and overall percentage growth arrest and limb length discrepancy compared to 5 fractions alone. CONCLUSIONS: These results support further investigation of amifostine and other radioprotectants in combination with fractionation for use in growing children requiring radiotherapy to the extremity for malignant tumors.

Dose response of amifostine in protection of growth plate function from irradiation effects.

The dose-response radioprotectant effects of amifostine on rat growth plate have not been studied. The purpose is to examine the relative effects of varying doses of amifostine on functional damage to the Sprague-Dawley rat growth plate from a single fraction radiation exposure. Thirty-six weanling Sprague-Dawley rats underwent single dose 17.5 Gy radiation exposure to the right knee. The contralateral left limb served as the nonirradiated control. Six groups of six animals each received, 20 minutes before radiation exposure, intraperitoneally administered amifostine at the following doses: 0, 50, 100, 150, 200, and 250 mg/kg. Six weeks after treatment, the rats were euthanized and the lower limbs disarticulated, skeletonized, radiographed, and measured. Statistically significant dose-related differences were observed between amifostine dosage groups for mean right-side growth, growth-loss, and limb-length discrepancy. The mean right-side growth recovered by amifostine administration increased from 14% at 50 mg/kg to 57% at 250 mg/kg. Growth-loss and limb discrepency were significantly reduced in proportion to increasing amifostine doses. Despite these positive effects of amifostine, amifostine associated mortality was identifiable beginning at 200 mg/kg and increased rapidly thereafter. This report suggests a directly proportional relationship between amifostine dose and its protective effects on the growth plate. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 73-79 (2000).

Humeral blade plate fixation of intercalary allografts and segmentally comminuted proximal humeral fractures: a preliminary report.

The AO 90 degrees humeral blade plate is a relatively new device, whose primary indication and previously described use is for proximal humeral fracture non-union. This study describes the use of the humeral blade plate for extended indications-fixation of segmentally comminuted proximal humeral fractures in two patients and fixation of humeral intercalary allografts after primary humeral neoplasm resection in three patients. A mean follow-up of 20 months revealed union in both fractures and five of the six allograft-host junctions. One patient required subsequent bone grafting for non-union at a proximal allograft-host junction. Functional results were excellent in three patients, good in one, and fair in one. Problems encountered intraoperatively were directly related to the limited array of implants. The long plates which were needed had blades which were too long and required intra-operative trimming in three cases. In four cases, additional plates were used to supplement the blade plate for distal fixation. In conclusion, the humeral blade plate is a useful device for fixation in these extended indications, but longer plates with 30.0 and 40.0-mm blade lengths should be made available.

Fibroma of tendon sheath of the infrapatellar fat pad.

We report on a 13-year-old boy who was found to have a fibroma of the tendon sheath associated with the patellar tendon and within Hoffa's fat pad of the knee. This benign tumor has never been described in this location previously. The MRI characteristics are correlated with the histologic findings.