Introduction

CT guided percutaneous radiofrequency thermo coagulation is the treatment of choice for osteoid osteomas. Good results with a low complication rate have been shown for spinal lesions. When lesions are within close proximity to neurological structures or if patients have radicular symptoms surgery rather than radiofrequency ablation has been advocated. We present our experience of radiofrequency ablation of spinal osteoid osteomas which are less than 5mm from neurological structures, including those causing radicular symptoms.

Simple bone cysts are relatively common in children. When they present to a musculoskeletal oncology unit, they are usually treated by a variety of methods that range from observations following fracture to surgically curettage. The outcome is usually good.

Very little is written in the literature regarding adults with a cystic bone lesion.

We present 10 consecutive skeletally mature patients who presented with a benign cystic bone lesion. The mean age at diagnosis was 38 years (20–60 years). Three patients has a cyst in the foot, three in the hip, two in the knee, one in the pelvis and the remainder in the shoulder. Full work up, including biopsy, was performed in all cases. All hip lesions required internal fixation for actual or impending fractures. The average follow up was 1.5 years. The surgical outcome was good in all cases.

The histological features are similar in all cases. Cementum, as found in Unicameral Bone Cysts, is not seen. This may present a new entity that is not described in the literature.

Introduction

Chondroblastomas are rare bone tumours accounting for approximately 1% of all benign bone lesions. They occur in children and adolescents and are more frequent in males.

The conventional treatment for chondroblastomas is surgery, however, this can be difficult and disabling due to the apo- or epiphyseal location. Surgery is curative in most cases, but recurrence rates of 10%–35% have been reported in the literature. Radiofrequency ablation is well established in the treatment of osteoid osteomas and painful bone metastases. We report our experience with the use of radiofrequency ablation in the treatment of chondroblastomas.

Objective

To evaluate the rise in impedance during percutaneous radiofrequency thermo coagulation (PRFTC) of osteoid osteomas as a predictor of local recurrence.

Introduction

Enchondromas located in the phalangeal bones may be more cellular than non-digital locations necessitating clinical and radiological correlation to determine diagnosis. Atypical enchondromas have increased cellularity and atypia relative to simple enchondromas but no evidence of permeation. Chondrosarcomas of the phalanges are thought to have a more indolent course than chondrosarcomas in other locations. The aim of the study was to determine the outcome of atypical enchondromas and grade 1 chondrosarcomas of the phalanges treated surgically.

CT guided percutaneous radiofrequency thermocoagulation is the treatment of choice for osteoid osteomas. Good results with a low complication rate have been shown for spinal lesions. When lesions are within close proximity to neurological structures or if patients have radicular symptoms surgery rather than radiofrequency ablation has been advocated. We present our experience of radiofrequency ablation of spinal osteoid osteomas which are less than 5mm from neurological structures, including those causing radicular symptoms.

Data was collected prospectively on all patients with a spinal osteoid osteoma within 5mm of nerve roots or the spinal cord as measured on CT scanning.

There were nine patients, five female and four male with a mean age of 15 years. Four tumours were located in the thoracic spine, three in the lumbar spine and two in the cervical spine. The mean distance to the nearest neurological structure was 3mm. Radicular symptoms were present in two patients. The mean number of probe positions used was two. Lesions were heated to 90 degrees for 5 minutes for each probe position. There were two cases of recurrence, both treated successfully with one further procedure each. There were no cases of neurological injury. The two patients with radicular symptoms had full resolution of their symptoms. At a mean follow up of 2 years following treatment all patients are asymptomatic.

Radiofrequency ablation can be safely performed to treat osteoid osteomas located within 5mm of neurological structures and has a low rate of recurrence.

Our study sets out to show whether vascular endothelial growth factor (VEGF) expression in stage 2B osteosarcomas around the knee influences disease-free and overall survival.

Fifty-two such patients treated in out unit were identified and followed-up for for a minimum of 92 months. All were treated according to the current MRC protocol and had resection of their tumour. Tissue from their resected tumours was stained for VEGF using immunohistochemical methods and the percentage of tumour cells staining for VEGF was assessed. The relationship between VEGF expression and survival was assessed using the log-rank test and Kaplan-Meier survival curves.

At follow-up 32 (62%) patients were dead, all from metastatic disease. Twenty-six (50%) tumours showed expression of VEGF. Statistical analysis showed that patients with tumours with VEGF expression in more than 25% of the cells had significantly shorter overall survival (p=0.019) and disease free intervals (p=0.009). Expression of VEGF also correlated with expression of the proteolytic enzyme MMP9 (p=0.02).

VEGF is peptide which acts as a stimulator of new blood vessel growth in normal tissues, as well as in some solid tumours and their metastases. A tumour which is able to induce a blood supply has an increased ability to grow, seed metastases and threaten life. Our study is the first to look at VEGF expression in the tumour cells surviving after chemotherapy. It is this population of cells which is important as it is these cells which may go on to develop into metastatic or locally recurrent tumours. The over-expression of VEGF by osteosarcoma cells is thought to be associated with a worse prognosis due to a number of mechanisms. This study shows that VEGF expression is an important prognostic factor in osteosarcomas and suggests that the mechanisms by which VEGF and MMP9 expression produce a poor prognosis may be linked. Suppression of tumour angiogenesis by inhibition of the action of VEGF has shown promise in animal models as a potential new treatment for osteosarcoma, and warrants further study.

Background: Growth and development of the intervertebral disc and its adjacent vertebrae is regulated via relative levels of cell proliferation, cell death and hypertrophy, and through extracellular matrix synthesis or degradation [1]. The synthesis of matrix molecules in the growing spine of embryonic rats has been reported in some detail [2,3]. In addition, increased levels of apoptotic disc cell death have been described in normal ageing, disc degeneration and in a murine model of disc spondylosis [4,5]. However, levels of cell proliferation in the developing spine have not been formally investigated.

Methods/Results: BALB/c mice were injected with the thymidine analogue, bromodeoxyuridine (BrdU), at weeks 1–4 postnatally and killed 1 or 24 hours later. The lumbar spines were decalcified and tissue sections immunostained for BrdU-incorporation. The intervertebral disc was fully formed at weeks 1–4, consisting of a notochordal nucleus pulposus, lamellar anulus fibrosus, and cartilaginous endplates between the disc and vertebral growth-plates. BrdU-immunopositivity was most marked in 1 week old mice, particularly in the proliferative zone of the growth-plate and the apophyseal ring. By 4 weeks, few, if any, BrdU-labelled cells were present in the disc, but some positivity remained in the apophyses. There were more paired BrdU-labelled cells at 24 hours than 1 hour post-injection in all regions, indicating likely clonal growth of these cells.

Conclusions: Cell proliferation forms an important part of the growth of the vertebrae, but also features in the early postnatal growth of the murine intervertebral disc. An understanding of how proliferation in these cell populations is regulated will help augment repair and regenerative responses in damaged adult discs or scoliosis.

Aims: The purpose of this study is to investigate whether the expression of MMP-9 (matrix metalloproteinase-9) is a potentially useful marker in osteosarcomas. Methods: 55 patients with stage IIB knee osteosarcomas were treated in our unit and had a median follow-up of 68 months. In addition to clinical data, MMP-1, MMP,-2, MMP-3, MMP-7, MMP-9 and MMP-13 were studied in the resection specimens, using immunohistochemical methods. The importance of all factors was studied using the log-rank test, and the overall survival of patients was calculated using Kaplan-Meier survival curves. Multiple variable analysis was carried out using Cox regression models with variables chosen forward and backward stepwise methods with deviance statistics. Signiþcance was set at p< 0.05. Results: On multiple variable analysis only the MMP-9 status of the tumour cells had a signiþcant effect on overall (p=0.032) and disease free survival (p=0.014). Conclusions: Our study shows that some post-chemotherapy osteosarcoma specimens express MMP-9 in the surviving tumour cells after chemotherapy. We believe that MMP-9 in the osteosarcoma cells which survive chemotherapy, contributes to recurrence because of the ability of these cells, to stimulate a new vascular network. The relationship between osteosarcomas and MMP-9 is worthy of further study.

Significant controversy exists with regard to the nomenclature, treatment and outcome of a group of well-differentiated lipomatous tumours sometimes labeled as atypical lipomas. The purpose of this paper is to attempt to clarify these controversies by reporting our experiences with this lesion.

The clinical features and follow-up of seventy patients with the diagnosis deep atypical lipoma (DAL) and a minimum two-year follow-up were examined.

Sixty- one patients were treated here with their primary lesion. Thirty-three were female and 28 were male. Ages ranged from 11 to 83 years (mean 57 years). They typically presented with a long history (four weeks to ten years, mean 91 weeks) and a large mass (4 to 30 centimetres, mean 18 centimetres). Most lesions were located in the thigh. Following treatment by marginal excision alone, five patients had a local recurrence (8.2%). Three recurred once and two recurred twice. No patient had a metastasis or died as a result of the tumour. No lesion dedifferentiated. Eight of the nine patients seen here with a presumed recurrence actually had a recurrent atypical lipoma. All recurrences were treated by further marginal resections and one went on to have a further recurrence. None of these patients had a metastasis and no lesion dedifferentiated. The final patient with a suspected recurrence most likely had a radiation-induced sarcoma nine years following radiotherapy after the marginal excision of a recurrent atypical lipoma.

We believe the term atypical lipoma is appropriate for these tumours, as they appear not to have any metastatic potential, merely a propensity to recur locally. The chance of dedifferentiation is small and the role of radiotherapy in the causation of dedifferentiation is uncertain. We suggest that a simple marginal resection (shelling-out) is adequate treatment for these lesions. Radiotherapy should not be used.