Multifocal primary bone sarcoma in the elderly: a rare case and review of the literature.

To our knowledge there are no reports of a primary multifocal spindle cell sarcoma affecting both long bones of the lower limb in an elderly patient. An 83-year-old man presented with a progressively painful right ankle, without a history of trauma. Radiographs demonstrated a pathological fracture through a mixed lytic and sclerotic lesion in the distal tibia. Staging investigations, including bone scintigraphy and magnetic resonance imaging, revealed a second lytic lesion in the right distal femur. A provisional diagnosis of metastatic disease was favoured and intramedullary nailing was considered. However, computed tomography of the chest, abdomen and pelvis, and relevant blood tests revealed no evidence of a primary malignancy. Open biopsy of the tibial lesion showed high-grade pleomorphic spindle cells consistent with a primary bone sarcoma. The patient was treated successfully with a right trans-femoral amputation. In conclusion, we recommend early bone biopsy to allow accurate diagnosis and appropriate skeletal management in elderly patients.

Primary extra-cranial meningioma following total hip replacement.

A 61-year-old man presented with pain at the left hip and decreased mobility 10 years after total hip replacement. Imaging demonstrated a large destructive expansile mass adjacent to the prosthesis. Histological analysis confirmed the presence of an extra-cranial meningioma. Primary tumours after total hip replacement are rare and include soft tissue sarcomas, bone sarcomas and lymphomas. To our knowledge, no previous cases of primary extracranial meningioma have been identified. The imaging features, histology, pathogenesis and differential diagnosis are discussed.

Malignant peripheral nerve sheath tumour in the ischio-rectal fossa.

Primary sarcomas in the ischiorectal fossa are occasionally reported and represent a significant challenge due to the proximity of rectum, levator muscles and pudendal neurovascular structures. We report a case in which the diagnosis changed between biopsy (desmoid tumour) and resection (malignant peripheral nerve sheath tumour), requiring a multidisciplinary surgical approach involving different sub-specialties. It also illustrates the importance of undertaking sarcoma surgery in a recognized sarcoma centre with sarcoma expertise available across a range of disciplines.

Disorders of the sternoclavicular joint.

The sternoclavicular joint is vulnerable to the same disease processes as other synovial joints, the most common of which are instability from injury, osteoarthritis, infection and rheumatoid disease. Patients may also present with other conditions, which are unique to the joint, or are manifestations of a systemic disease process. The surgeon should be aware of these possibilities when assessing a patient with a painful, swollen sternoclavicular joint.

MRI surveillance after resection for primary musculoskeletal sarcoma.

This study reports the experience of one treatment centre with routine surveillance MRI following excision of musculoskeletal sarcoma. The case notes, MRI and histology reports for 57 patients were reviewed. The primary outcome was local tumour recurrence detected on either surveillance MRI in asymptomatic patients, or interval MRI in patients with clinical concern. A total of 47 patients had a diagnosis of soft-tissue sarcoma and ten of a primary bone tumour. A total of 13 patients (22%) had local recurrence. Nine were identified on a surveillance scan, and four by interval scans. The cost of surveillance is estimated to be pound4414 per recurrence detected if low-grade tumours with clear resection margins are excluded. Surveillance scanning has a role in the early detection of local recurrence of bone and soft-tissue sarcoma.

Endometriosis of the superior gluteal nerve.

Endometriosis that involves nerves is rare and usually occurs in the pelvis. We describe a case of extra-pelvic endometriosis that involved the superior gluteal nerve. The patient presented with ill-defined buttock and thigh pain and a Trendelenberg gait. MRI demonstrated atrophic changes in the gluteus minimus, gluteus medius and tensor fascia lata muscles indicating involvement of the superior gluteal nerve. MRI showed a mass in the line of the superior gluteal nerve. The mass was hyperintense on STIR and T1-weighted images and did not enhance after intravenous contrast although surrounding edema did enhance. Histological examination of material obtained at open biopsy showed endometriosis. The patient was commenced on hormonal treatment to suppress ovarian activity.

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

OBJECTIVE: To 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 PATIENTS: Thirty-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. RESULTS: The mean age at presentation is 43 years. 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. CONCLUSIONS: Although 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.

Detection of intraarticular bodies of the elbow with saline arthrosonography.

AIM: To assess whether ultrasound with intraarticular injection of saline increases the detection of intraarticular bodies of the elbow. SUBJECTS AND METHODS: Twelve patients (age range 21-42 years, mean 29 years; 8 male, 4 female) referred over a 2-year period with an equivocal history of elbow locking and plain radiographs had a joint injection of at least 12 ml of sterile saline during ultrasound examination. No patient had a joint effusion before injection. Surgical correlation was available in six patients. RESULTS: Ten patients had intraarticular bodies but these were demonstrated only after joint injection in six patients. Arthroscopy performed in six patients confirmed intraarticular bodies in five. Radiographs were falsely positive in one and falsely negative in seven patients. CONCLUSION: Joint injection improves the sonographic evaluation and conspicuity of small and radiographically occult intraarticular loose bodies in the clinically equivocal elbow. The procedure is simple, quick, well tolerated and reproducible.

Synovial desmoplastic fibroblastoma of hip joint with bone erosion.

A 78-year-old woman presented with pain at the left hip. Initial radiographs showed minimal age-related changes. Over the next 2 years she developed large erosions in the left femoral neck and proceeded to hip replacement. Histological examination showed bland spindle cells in a loose and hyalinised collagenous stroma considered to represent a desmoplastic fibroblastoma (collagenous fibroma). This is the first reported case of synovial desmoplastic fibroblastoma.

Sonographic appearances of nerve tumors.

This article reviews the clinical and sonographic features of neurilemoma, neurofibroma, intraneural ganglion, traumatic neuroma, and Morton's neuroma. The sonographic characteristics and location at typical sites are important diagnostic features for nerve tumors.

Non-communicating intramuscular ganglia.

Intramuscular ganglia are rare. Most of the previously reported cases were connected with an adjacent joint. We present the imaging findings in three patients who had intramuscular ganglia that were not connected with a joint. Magnetic resonance showed a septated, encapsulated mass that was isoor hypointense to muscle on T1-weighted and hyperintense on T2-weighted images. A post-contrast T1-weighted scan in one patient showed minimal capsular enhancement. Ultrasound performed in one case showed an encapsulated, anechoic mass.

The ring sign: a new ultrasound sign of peripheral nerve tumours.

The ultrasound ring sign is reported in two patients with benign nerve tumours. The echogenic ring lies within the mass rather than at its periphery. This appearance has not been described previously in nerve tumours.

Diffuse neurofibroma of the ankle.

PURPOSE: To correlate the imaging and histological findings in diffuse neurofibroma. PATIENTS AND METHODS: Retrospective review of clinical, imaging and histological findings in two patients with diffuse neurofibroma. RESULTS: CT demonstrates diffuse infiltration of the deep and subcutaneous fat, isodense to muscle. Magnetic resonance imaging shows extensive infiltration of the subcutaneous and deep fat that envelops tendons and vessels but does not involve bone. Superficial masses enhance homogeneously after intravenous gadolinium. The reticular nature of the deep infiltration is seen on all sequences but is most conspicuous on post-gadolinium T1-weighted images which show tumour enhancement and non-enhancing hypointense soft tissue strands. Magnetic resonance angiography and Doppler ultrasound may show enlarged vessels, high blood flow and vascular pools. CONCLUSION: Diffuse neurofibroma has a characteristic appearance on magnetic resonance that is best shown on post-gadolinium T1-weighted images.

Posterior vertebral rim fractures.

Fracture of the posterior vertebral endplate is a cause of low back pain in adolescents and young adults. Clinically it resembles an acute disc prolapse with low back pain and radiculopathy, but may present with neurogenic claudication due to spinal stenosis in older patients. The lesions may be incidental findings. Plain radiographs are diagnostic in about 40% of cases. CT shows the fracture fragment and vertebral defect in most cases but the fracture fragment may be overlooked on MRI. Accurate diagnosis is essential as the surgical technique for disc herniation is inadequate for endplate fractures. In this pictorial essay we review the imaging findings.

Ultrasound in the assessment of metatarsalgia: a surgical and histological correlation.

AIMS: To assess the reliability of ultrasound in the evaluation of metatarsalgia in a typical clinical setting. METHODS AND MATERIALS: The clinical records, ultrasound findings, surgical outcome and histology of patients with metatarsalgia referred for ultrasound evaluation were reviewed. All ultrasound examinations were performed by the same operator via a plantar approach using high resolution linear array probes. RESULTS: Thirty-seven patients were examined, age range 23 to 74, mean 49.6 years; thirty-one were female. Thirty-seven intermetatarsal masses were found in 32 patients. To date 26 patients have undergone surgery and 28 lesions (26 Morton's neuromas, one angiolipoma and one angioleiomyoma) have been excised. There were no false-positive ultrasound examinations. A solitary neuroma was missed. Sensitivity was 96% and positive predictive value 100%. CONCLUSION: Ultrasound is a valuable tool in the evaluation of metatarsalgia and has high sensitivity and positive predictive value for the detection of intermetatarsal masses. It provides exact localization prior to surgical resection and detects unsuspected additional lesions.

Synovial presentation of non-Hodgkin's lymphoma.

The MRI appearances of synovial involvement from non-Hodgkin's lymphoma are described in a 61-year-old man. These appearances have not previously been described and the differential diagnosis is discussed.