Pathologic fracture of a calcaneal aneurysmal bone cyst.

A 21-year-old man presented with a pathologic fracture through the posterior aspect of the calcaneus into an aneurysmal bone cyst. The patient was treated using curettage, phenol, alcohol, and burr with open reduction and internal fixation. This is the first reported case of a pathologic fracture of an aneurysmal bone cyst of the calcaneus, highlighting the fracture potential of these lesions and the need for early management.

Gender-specific activity of chemotherapy correlates with outcomes in chemosensitive cancers of young adulthood.

Good evidence indicates that adolescents and young adults (AYAs) with cancer do badly compared with children with similar cancers. The reasons are poorly understood. Australian registry data on 14,824 cancers of adolescence and young adulthood seen between 1982 and 2002 were reviewed. A detailed substudy of clinical characteristics was analyzed from 179 AYAs with Hodgkin lymphoma (HL), Ewing sarcoma (ES) or osteosarcomas (OS) treated at a single institution. Despite significant improvements in survival for both groups over the period in question, for acute lymphoblastic leukaemia, rhabdomyosarcoma, ES, OS and HL, survival for AYAs was worse than for children. For ES, OS and HL, the survival gap occurred almost entirely in males (Hazard ratios compared with female AYAs of 1.8 [p < 0.01], 1.4 [p = 0.03] and 1.5 [p < 0.01] respectively). Survival outcomes from ES, OS and HL for female AYAs were not significantly different from children of either sex. For brain tumors and thyroid cancers, which are primarily treated surgically, there were no gender-related differences in outcomes. Although no differences in tumor stage or compliance were identified, male AYAs experienced less toxicity and lower response rates to chemotherapy (p = 0.008). Young males account almost entirely for excess mortality from chemosensitive cancers of adolescence and young adulthood compared to children, which may be due to relative underdosing with current chemotherapy dosing algorithms.

Parosteal lipoma associated with an underlying osteochondroma arising from the hallux.

Parosteal lipomas are rare benign tumours of mature adipose tissue that arise in continuity with the underlying bone. These lesions represent less than 0.3% of all lipomas and commonly arise in the femur, tibia, humerus and radius. There have been no reported cases of such lesions arising in the foot. Hence, we report the first case of a parosteal lipoma arising in the great toe in association with an underlying osteochondroma.

Multidisciplinary approach to diagnosis and management of osteosarcoma - a review of the St Vincent's Hospital experience.

BACKGROUND: Osteosarcoma is the most common primary malignant bone tumour in children and young adults. Despite advances in the diagnosis and management of osteosarcoma, there have been few recent studies describing the experiences of tertiary referral centres. This paper aims to describe and discuss the clinical features, pre-operative work-up, management and outcomes of these patients at St Vincent's Hospital (Melbourne, Australia). METHODS: Retrospective study of fifty-nine consecutive patients managed for osteosarcoma at St Vincent's Hospital between 1995 and 2005. RESULTS: Median age at diagnosis was 21 (range, 11-84) years. Gender distribution was similar, with thirty-one male and twenty-eight female patients.Twenty-five patients had osteosarcoma in the femur, eleven each were located in the humerus and tibia, six were identified in the pelvis, and one each in the clavicle, maxilla, fibula, sacrum, ulna and radius.Pre-operative tissue diagnosis of osteosarcoma was obtained through computed tomography-guided percutaneous biopsy in over ninety percent of patients. Following initial therapy, over fifty percent of patients remained relapse-free during the follow-up period, with twelve percent and twenty-seven percent of patients documented as having local and distant disease recurrence, respectively. Of patients with recurrent disease, sixty-two percent remained disease-free following subsequent surgical intervention (most commonly, pulmonary metastatectomy). CONCLUSION: Patient outcomes can be optimised through a multidisciplinary approach in a tertiary referral centre. At St Vincent's Hospital, survival and relapse rates of patients managed for osteosarcoma compare favourably with the published literature.

Percutaneous radiofrequency ablation for osteoid osteoma: experience with a new treatment.

OBJECTIVE: To review our experience with percutaneous radiofrequency ablation (RFA) for osteoid osteoma. PARTICIPANTS, DESIGN AND SETTING: Retrospective review of 24 patients with osteoid osteoma treated with percutaneous RFA at St Vincent's Hospital, Melbourne, from August 2000 to February 2005. MAIN OUTCOME MEASURES: Initial response to treatment, return of symptoms, time to recurrence, complications and histopathological correlation. RESULTS: In 23 of 24 patients, there was immediate relief of symptoms. One-third of patients had a return of symptoms. The 24 patients underwent a total of 32 RFA procedures. Of the eight patients who had a recurrence, five had an initial lesion > or = 10 mm in maximum diameter. Twenty-three of the 24 patients were pain-free at the end of the study period. Patients were followed up for a median of 26 months. There were no long-term complications. CONCLUSIONS: Percutaneous RFA is a safe and efficacious treatment for osteoid osteoma with a low morbidity rate. Despite recurrence after treatment, re-treatment is simple and effective.

Femoral mesenchymal chondrosarcoma with secondary aneurysmal bone cysts mimicking a small-cell osteosarcoma.

Mesenchymal chondrosarcoma is a rare but aggressive, high-grade malignancy of primitive cartilage-forming mesenchyme that arises most commonly from skeletal sites. Although there are radiological findings suggestive of the diagnosis, imaging features often overlap with those of other skeletal sarcomas. The definitive diagnosis relies on the histological finding of a typical bimorphic appearance, consisting of nests of small, round, poorly differentiated cells and more mature cartilaginous tissue. To highlight this, we present the case of a 21-year-old man who was referred to our institution with a history of right knee pain. Initial imaging and histological evaluation of a core biopsy of the lesion suggested osteosarcoma of the distal right femur; after review, however, the correct diagnosis of mesenchymal chondrosarcoma was made. Adequate tissue sampling and thorough histological evaluation of biopsy specimens is vital for the accurate diagnosis of primary bone malignancies, especially those of chondroid origin.

Osteosarcoma near joints: assessment and implications.

BACKGROUND: The choice of performing surgery when tumors encroach onto joints remains a challenging and controversial issue. Pre-operative assessment by magnetic resonance imaging (MRI) is of critical importance in dictating surgical management and subsequent functional outcome. METHODS: We examined archival samples from 27 patients with osteosarcoma, adjacent to synovial joints for the incidence and mechanism of osteosarcoma extension into the joint space. Histopathologic findings were correlated with pre-operative MRI findings and choice of operation. RESULTS: There was no evidence of penetration across the entire thickness of articular cartilage into the joint cavity in all of the 27 cases. When pre-operative MRI confidently excluded joint involvement by tumor, enabling an intra-articular surgical approach, histopathologic correlation confirmed the absence of joint involvement in all cases. The low incidence of joint involvement was despite the presence of extensive bone and soft tissue involvement in most cases, a tendency for peripheral extension of tumor around the articular margin of the bone, and evidence of joint effusions pre-operatively in more than one-third of cases. CONCLUSIONS: Joint involvement by osteosarcoma is uncommon, with articular cartilage being a relative barrier to tumor invasion. If pre-operative MRI does not show definite evidence of intra-articular tumor involvement, it is likely to be safe to proceed with intra-articular resection.

Tuberculosis masquerading as malignancy: a multimodality approach to the correct diagnosis - a case report.

BACKGROUND: Extrapulmonary tuberculosis is one of the great mimickers of medicine, and often masquerades as malignancy. As a result, patients may be referred to oncologists and surgeons for further evaluation and management, delaying the institution of appropriate anti-tuberculous drug therapy. CASE PRESENTATION: We present the case of a 21 year old man with tuberculous osteomyelitis, who was referred to the Bone and Soft Tissue Sarcoma Service at our institution with a provisional diagnosis of malignancy. Further investigation revealed extensive retroperitoneal abdominal and pelvic lymphadenopathy. The recognition of certain patterns on imaging, and finally the isolation of Mycobacterium tuberculosis from tissue samples obtained under image guidance, enabled the correct diagnosis to be made. CONCLUSION: This case highlights the importance of remaining cognisant of the protean manifestations of extrapulmonary tuberculosis, and illustrates the advantage of a clinically directed multi-modality imaging approach to diagnosis.

Accuracy of computed tomography guided core needle biopsy of musculoskeletal tumours.

BACKGROUND: The accurate diagnosis of musculoskeletal tumours is important for successful treatment. Image guided biopsy is gaining increasing acceptance for obtaining tissue for diagnosis. The aim of the present study is to assess the accuracy of computed tomography (CT)-guided core needle biopsy of musculoskeletal tumours. METHODS: This is a retrospective study on a series of 127 patients with a musculoskeletal tumour. The biopsies were performed over a 4-year period from 1998 to 2001. The accuracy of the CT-guided core needle biopsy was determined by comparing the histology of the biopsy with the final histology of the specimen obtained at open biopsy or surgical resection of the tumour. The effective accuracy was determined by the accuracy of the biopsy to distinguish between a benign and malignant tumour. RESULTS: Computed tomography guided core needle biopsy in the present series has an overall accuracy of 80.3%. The effective accuracy as determined by a malignant versus benign lesion was 89%. There were 86 malignant tumours with a biopsy accuracy of 81.4% and there were 41 benign tumours with a biopsy accuracy of 78%. The positive predictive value (PPV) of a malignant tumour is 98.9% and the PPV of benign tumour 90.2%. The most common site of biopsy was from the femur and thigh, together accounting for 39.4% of the tumours. The most common tumours in this series were liposarcoma (n = 12), osteosarcoma (n = 11) and giant cell tumour (n = 11). There were no reported complications arising from the biopsy. CONCLUSION: Computed tomography guided core needle biopsy is a safe and effective procedure that is important in the diagnosis and management of musculoskeletal tumours. It should be performed in a specialized institution with a multidisciplinary musculoskeletal tumour team.