D. C. Mangham

Risk factors for survival and local control in chondrosarcoma of bone

We studied 153 patients with non-metastatic chondrosarcoma of bone to determine the risk factors for survival and local tumour control. The minimum follow-up was for five years; 52 patients had axial and 101 appendicular tumours. Surgical treatment was by amputation in 27 and limb-preserving surgery in 126. The cumulative rate of survival of all patients, at 10 and 15 years, was 70% and 63%, respectively; 40 patients developed a local recurrence between 3 and 87 months after surgery and 49 developed metastases. Local recurrence was associated with poor survival in patients with concomitant metastases but not in those without. On multivariate analysis independent risk factors for rates of survival include extracompartmental spread, development of local recurrence and high histological grade. Independent risk factors for local recurrence include inadequate surgical margins and tumour size greater than 10 cm. Location within the body, the type of surgery and the duration of symptoms are of no prognostic significance. Surgical excision with an oncologically wide margin provides the best prospect both for cure and local control in these patients.

Osteosarcoma of the pelvis

AIMSnOsteosarcoma of the pelvis is a particularly difficult tumour to treat as it often presents late, may be of considerable size and/or associated with metastases when it presents, and is frequently chondroid in origin and resistant to chemotherapy. The aim of this study was to review our experience of managing this group of patients and to identify features predictive of a poor outcome.nnnPATIENTS AND METHODSnBetween 1983 and 2014, 121 patients, (74 females and 47 males) were treated at a single hospital: 74 (61.2%) patients had a primary osteosarcoma and 47 (38.8%) had an osteosarcoma which was secondary either to Pagets disease (22; 18.2%) or to previous pelvic irradiation (25; 20.7%). The mean age of those with a primary osteosarcoma was 29.3 years (nine to 76) and their mean follow-up 2.9 years (0 to 29). The mean age of those with a secondary sarcoma was 61.9 years (15 to 85) and their mean follow-up was one year (0 to 14). A total of 22 patients with a primary sarcoma (52.4%) and 20 of those with a secondary sarcoma (47.6%) had metastases at the time of presentation.nnnRESULTSnThe disease-specific survival at five years for all patients was 27.2%. For those without metastases at the time of diagnosis, the five-year survival was 32.7%. Factors associated with a poor outcome were metastases at diagnosis and secondary tumours. In primary osteosarcoma, sacral location, surgical margin and a diameter > 10 cm were associated with a poor outcome.nnnCONCLUSIONnIn this, the largest single series of patients with an osteosarcoma of the pelvis treated in a single hospital, those with secondary tumours and those with metastases at presentation had a particularly poor outcome. For those with a primary sarcoma, sacral location, an intralesional margin and a diameter of > 10 cm were poor prognostic indicators.

Intraosseous lipoma: report of 35 new cases and a review of the literature

ObjectiveTo identify the common imaging features of intraosseous lipomas on radiographs, magnetic resonance imaging (MRI) and computed tomography (CT), and review their histological features.Design and patientsThirty-five previously unreported cases of intraosseous lipoma were reviewed and a meta-analysis was performed of another 110 cases identified from the English language literature.ResultsThe mean age at presentation is 43xa0years. Sex distribution is nearly equal. Lipomas occur most frequently in the lower limb (71% overall), particularly in the os calcis (32%). Other common sites include the metaphyses of long bones, where lesions are typically eccentric. Lipomas are usually well defined, but marginal sclerosis is commoner in lesions of the os calcis (61%) than at other sites (38%). Calcification is also more frequent in the os calcis (62%), and almost invariably centrally located. Calcification at other sites is less common (30%), and is more variable in appearance. Bone expansion is less common (30%), and usually minimal. Fat necrosis and cyst formation identified on MRI is common (67%), and more frequent in the os calcis.ConclusionsAlthough there is correlation between the histological and radiological features of intraosseous lipomas in general, some discrepancies occur in the radiological appearances of lipomas in different sites. The evidence that these lesions are true benign tumours of fat is controversial. Several aetiological factors have been implicated in their development. The constant location of os calcis lesions at the critical angle suggests an aetiology that may be related to biomechanical lines of stress. In other instances it is possible that involution of pre-existing lesions may lead to the development of lipomas.

Experience in the treatment of dedifferentiated chondrosarcoma

Dedifferentiated chondrosarcoma is a rare, highly malignant variant of chondrosarcoma in which a high-grade spindle-cell sarcoma coexists with a lower-grade chondroid tumour. We have reviewed our experience with this neoplasm in 22 patients, all of whom were treated using modern oncological principles of planned resection and chemotherapy. Despite this the median survival was under nine months and only 18% were alive at five years. Those patients who received chemotherapy, and in whom wide margins of excision were achieved at operation, did best. It is essential to have an accurate preoperative diagnosis in order to plan treatment which may offer a better prospect of cure.

The 'penumbra sign' on T1-weighted MR imaging in subacute osteomyelitis : Frequency, cause and significance

OBJECTIVEnWe studied the frequency and cause of a feature exhibited on T1-weighted (T1-W) magnetic resonance (MR) imaging termed the penumbra sign in a series of patients presenting with osteomyelitis and correlated it with the double-line sign described as a T2-weighted (T2-W) or short tau inversion recovery (STIR) feature of both the Brodies abscess and avascular necrosis.nnnMATERIALS AND METHODSnThe clinical, radiographic, MR imaging, microbiological and histological findings in 32 patients referred to an orthopaedic oncology service, but subsequently proven to have osteomyelitis, were reviewed. The presence or absence of a rim of tissue lining an abscess cavity typified by minor signal hyperintensity relative to the main abscess contents on T1-W MR imaging (the penumbra sign) was identified. The sign was correlated with the radiographic and other findings.nnnRESULTSnThe penumbra sign was identified in 24 cases (75%) and appears to be a more sensitive sign than the corresponding double-line sign which was evident in only 29% of these on T2-W or fast STIR images. The lesions were unilocular in 11 cases (46%) and multilocular in 13 (54%). The thickness of the penumbra ranged from 2 to 5mm. On histological examination the tissue comprising the penumbra sign was found to be highly vascularized granulation tissue containing thick walled arterioles.nnnCONCLUSIONnThe penumbra sign is characteristically seen on T1-W MR images in subacute osteomyelitis and is due to a thick layer of highly vascularized granulation tissue which may not be visible as the double-line sign on T2-W or fast STIR sequences. This characteristic, but not pathognomonic, MR finding supports the diagnosis of bone infection and helps to exclude the presence of a tumour.

Primary synovial chondromatosis and synovial chondrosarcoma: a pictorial review

Abstract. This article illustrates the imaging characteristics of primary synovial chondromatosis (PSC) using 20 cases referred to a tertiary orthopaedic oncology centre. Three quarters of patients presented with a large intra-articular soft tissue mass and a suspected clinical and radiological diagnosis of malignancy made in the referring centres. Radiographs demonstrated fine cartilaginous mineralisation in the soft tissue masses in 85% cases and bone erosions were shown on MR imaging in 80%. Malignant transformation to chondrosarcoma was proven in 2 cases with longstanding disease. There were no specific MR features to distinguish these cases with malignant change from PSC alone. Primary synovial chondromatosis should be considered in the diagnosis of the monarticular presentation of an intra-articular soft tissue mass, particularly in the presence of superficial bone erosions and signal voids due to the mineralisation.

Stage-IIB osteosarcomas around the knee: A STUDY OF MMP-9 IN SURVIVING TUMOUR CELLS

We studied 55 patients with stage-IIB osteosarcoma around the knee with respect to the expression of matrix metalloproteinase (MMP)-9 in the surviving tumour cells in surgical resection specimens. They were followed up for a minimum of 2.5 years. Factors significantly associated with poor overall survival were a high serum level of alkaline phosphatase at diagnosis and tumour cells expressing MMP-9 in the resection specimens. The only factor strongly associated with disease-free survival was the immunohistochemical status of tumour cells for MMP-9 in the resection specimens. The percentage of necrosis after chemotherapy failed marginally to reach statistical significance. On Cox regression analysis only MMP-9 remained significant for overall and disease-free survival.

Imaging features of intraosseous ganglia: a report of 45 cases.

The aim of this study is to report the spectrum of imaging findings of intraosseous ganglia (IG) with particular emphasis on the radiographic and magnetic resonance (MR) features. Forty-five patients with a final diagnosis of IG were referred to a specialist orthopaedic oncology service with the presumptive diagnosis of either a primary or secondary bone tumour. The diagnosis was established by histology in 25 cases. In the remainder, the imaging features were considered characteristic and the lesion was stable on follow-up radiographic examination. Radiographs were available for retrospective review in all cases and MR imaging in 29. There was a minor male preponderance with a wide adult age range. Three quarters were found in relation to the weight-bearing long bones of the lower limb, particularly round the knee. On radiographs all were juxta-articular and osteolytic; 74% were eccentric in location, 80% had a sclerotic endosteal margin and 60% of cases showed a degree of trabeculation. Periosteal new bone formation and matrix mineralization were not present. Of the 29 cases that underwent MR imaging, 66% were multiloculated. On T1-weighted images the IG contents were isointense or mildly hypointense in 90% cases. Forty-one per cent of the cases showed a slightly hyperintense rim lining that enhanced with a gadolinium chelate. Thirty-eight per cent were associated with soft tissue extension and 17% with a defect of the adjacent articular cortex. Fifty-five per cent showed surrounding marrow oedema on T2-weighted or STIR images and two cases (7%) a fluid-fluid level prior to any surgical intervention. The authors contend that it is semantics to differentiate between an IG and a degenerate subchondral cyst as, while the initial pathogenesis may vary, the histological endpoint is identical, as are the imaging features apart from the degree of associated degenerative joint disease. IGs, particularly when large, may be mistaken for a bone tumour. Correlation of the typical radiographic and MR imaging features will indicate the correct diagnosis and obviate the need for biopsy.

SAPHO syndrome: 20-year follow-up

Abstractu2002Considerable attention has been paid in the past 10 years to the radiological spectrum of disease entities belonging to the SAPHO syndrome. We report an unusual case presenting with an extra-axial (femoral) lesion, prior to description of this syndrome, which was radiologically and histologically mistaken for a parosteal osteosarcoma. Nineteen years later, a further lesion developed in the scapula together with the typical sternoclavicular manifestations, at which stage the correct diagnosis of SAPHO syndrome was established.

Calcific myonecrosis: a report of ten new cases with an emphasis on MR imaging.

The aim of this study is to report the typical radiographic and MR imaging features of calcific myonecrosis, which help to distinguish this rare entity from other causes of a calcifying calf mass. Ten patients with a final diagnosis of calcific myonecrosis were referred to a specialist orthopaedic oncology service in a 5-year period with the presumptive diagnosis of malignancy based on recent clinical presentation and imaging findings. Radiographs were available for retrospective review in all ten cases and MR imaging in six. All patients presented with a slow-growing painless calf mass. All gave a history of major trauma to the lower leg many years before, but in only two cases did the referring clinician query whether trauma might be a contributory factor. Radiographs showed well-defined fusiform mineralised masses up to 25xa0cm in length arising within the calf. The calcification was consistently peripheral and plaque-like. Ossification was not present. MR imaging showed the anterior compartment to be involved in four cases and all compartments in two. T1- and T2-weighted images showed peripheral low signal intensity, more prominent on the T2-weighted images, because of the peripheral mineralization. The contents of the masses were variable on T1-weighted images depending on the differing amounts of blood breakdown products and were heterogeneous on T2-weighted images. The latter may be explained by a combination of the mineralisation and T2 shortening due to blood breakdown products. A gadolinium chelate, administered in two cases, failed to show any appreciable enhancement. Calcific myonecrosis has characteristic clinical, radiographic and MR features that should make the condition easy to recognise. Despite its rarity, it should be included in the differential diagnosis of focal mineralisation of the calf.