Update on the imaging features of the enchondromatosis syndromes.

Ollier disease and Maffucci syndrome are the commonest enchondromatosis subtypes, arising from non-hereditary mutations in the IDH1 and IDH2 genes, presenting in childhood and being characterised by multiple enchondromas. Maffucci syndrome also includes multiple soft tissue haemangiomas. Aside from developing bony masses, osseous deformity and pathological fracture, ~ 40% of these patients develop secondary central chondrosarcoma, and there is increased risk of non-skeletal malignancies such as gliomas and mesenchymal ovarian tumours. In this review, we outline the molecular genetics, pathology and multimodality imaging features of solitary enchondroma, Ollier disease and Maffucci syndrome, along with their associated skeletal complications, in particular secondary chondrosarcoma. Given the lifelong risk of malignancy, imaging follow-up will also be explored. Metachondromatosis, a rare enchondromatosis subtype characterised by enchondromas and exostoses, will also be briefly outlined.

Update on imaging of the cervical spine in rheumatoid arthritis.

Rheumatoid arthritis is a multisystem, autoimmune, inflammatory disorder with numerous musculoskeletal manifestations. Involvement of the cervical spine is common and may result in severe complications due to synovitis, erosions, pannus formation, spinal instability and ankylosis. The purpose of this article is to review the current role of imaging in the rheumatoid spine, with emphasis on radiographs and MRI.

The value of re-staging chest CT at first local recurrence of extremity and trunk soft tissue sarcoma.

OBJECTIVE: To determine the prevalence of pulmonary metastases on re-staging chest CT at the time of first local recurrence (LR) of trunk or extremity soft tissue sarcoma (STS). MATERIALS AND METHODS: Retrospective review of all patients diagnosed with recurrent STS between May 2007 and April 2018. Data collected included patient age and sex, site of primary STS, time to LR, recurrence site, initial tumour grade, recurrent tumour grade, findings of initial staging chest CT, and prevalence of pulmonary metastases on re-staging chest CT. RESULTS: The study included 109 patients (males = 68, females = 41; mean age 56 years, range 9-92 years). The commonest tumour sub-types were myxofibrosarcoma (27.5%), undifferentiated pleomorphic/spindle cell sarcoma (20.2%), synovial sarcoma (10.1%), and malignant peripheral nerve sheath tumour (10.1%). Initial staging chest CT demonstrated pulmonary metastases in 1 of 77 (1.3%) patients for whom CT was available for review. The mean time to LR was 30.8 months (range 3-224 months). Pulmonary metastases were diagnosed on re-staging chest CT in 26 of 109 cases (23.9%), being commonest with grade 3 STS (36.1%). Pleomorphic sarcoma (85.7%) and undifferentiated spindle cell sarcoma (33.3%) were the 2 commonest tumour sub-types associated with pulmonary metastases at first LR. CONCLUSION: Re-staging chest CT at the time of first LR of STS identified a prevalence of 23.9% pulmonary metastases, which supports the need for chest CT at the time of LR in line with the UK guidelines for the management of bone and soft tissue sarcoma. KEY POINTS: • Pulmonary metastases were diagnosed in 1.3% of soft tissue sarcomas at presentation. • Pulmonary metastases were identified in ~ 24% of patients at first local recurrence of soft tissue sarcoma, most commonly with pleomorphic sarcoma and Trojani grade tumours. • No patient with a low-grade recurrence had pulmonary metastases.

An update on the imaging of diaphyseal aclasis.

Solitary osteochondromas are common, benign hyaline cartilage-capped exostoses that primarily arise from the metaphyses of long and flat bones. Diaphyseal aclasis is an autosomal dominant condition resulting from EXT1 or EXT2 gene mutations and is characterized by multifocal osteochondromas. These can result in a wide spectrum of complications, such as skeletal deformity, neurological and vascular complications, adventitial bursa formation, fracture, and rarely malignant transformation to peripheral chondrosarcoma. In this review, we outline in detail the multimodality imaging features of DA and its associated complications.

MRI features of low-grade and high-grade chondrosarcoma in enchondromatosis.

OBJECTIVE: To identify magnetic resonance imaging (MRI) features which aid differentiation of low-grade chondral tumours (LGCT-enchondroma and grade 1 chondrosarcoma) from high-grade chondral tumours (HGCT) in patients with enchondromatosis. MATERIALS AND METHOD: Approval from our local Research and Innovation Centre of The Institute of Orthopaedics was gained. Patients with enchondromatosis who had biopsy and/or resection of chondral lesions over a 13-year period were identified. The pre-biopsy MRI study was assessed by two experienced musculoskeletal radiologists for tumour origin (intramedullary or surface), cortical expansion, cortical destruction, bone marrow oedema, periosteal reaction, soft tissue mass and soft tissue oedema. MRI features were compared with the final histopathological diagnosis. RESULTS: The study group comprised 25 males and 16 females, with a mean age of 34.9 years (range 6-81 years). Fifty-nine lesions were assessed (12 patients had > 1 tumour treated), including 43 LGCT and 16 HGCT. Significant MRI features suggesting malignant transformation to HGCT for both observers included bone oedema (p = < 0.001 and 0.002), periosteal reaction (p = 0.01) and soft tissue oedema (p = 0.001 and 0.05). Cortical destruction and soft tissue mass were predictors of HGCT in major long bones, but no significant differentiating features were identified in the hands and feet. CONCLUSION: The presence of bone oedema, periosteal reaction and soft tissue oedema on MRI may indicate a high-grade malignant transformation of chondral tumours in patients with enchondromatosis.

MRI of the distal tibiofibular joint.

The distal tibiofibular joint is a fibrous joint that plays a crucial role in the stability of the ankle joint. It is stabilized by three main ligaments: the anterior inferior tibiofibular ligament, the posterior inferior tibiofibular ligament, and the interosseous tibiofibular ligament, which are well delineated on magnetic resonance imaging. Pathology of the distal tibiofibular joint is mostly related to trauma and the longer-term complications of trauma, such as soft tissue impingement, heterotopic ossification, and synostosis. This review article outlines the MRI anatomy and pathology of this joint.

Magnetic resonance imaging of the meniscal roots.

The meniscal roots and supporting structures anchor the menisci to the tibial plateau and resist hoop stress, thereby preventing radial displacement of the menisci and secondary degenerative tibiofemoral compartment changes that may occur if this is compromised. The anatomy of the four meniscal roots and their supporting structures on magnetic resonance imaging (MRI) will be outlined in this review article, as well as the imaging appearances of meniscal root-related pathology, namely meniscal root degeneration and tears, meniscal extrusion and tibial plateau cystic lesions.

The incidence of skip metastases on whole bone MRI in high-grade bone sarcomas.

INTRODUCTION: Skip metastases have been described with osteosarcoma, Ewing sarcoma and rarely chondrosarcoma. The aim of this study was to determine the incidence of skip metastases on whole bone MRI in all primary high-grade sarcomas of the major long bones. MATERIALS AND METHOD: Retrospective review of patients from April 2007 to April 2019 with high-grade primary bone sarcomas of the humerus, radius, ulna, femur, tibia or fibula who had whole bone MRI at initial staging. Data collected included age, sex, tumour type, presence and location of skip metastases based on whole bone MRI and presence of distant metastases (the skeleton and lung). RESULTS: The study included 216 males and 171 females with mean age 30.6 years (range 4-92 years). Tumour types were as follows: High-grade osteosarcoma n = 202, Ewing sarcoma n = 68, high-grade chondrosarcoma n = 44, dedifferentiated chondrosarcoma n = 37, high-grade spindle cell sarcoma n = 29 and angiosarcoma n = 7. Skip lesions were identified in 63 (16.3%). However, after taking into account the presence of distant skeletal (n = 11) and pulmonary (n = 33) metastases, the overall incidence of skip metastases was 6.5%, occurring in 15 (7.5%) high-grade osteosarcomas, 3 (4.5%) Ewing sarcoma, 1 (2.8%) high-grade chondrosarcoma, 4 (10.8%) dedifferentiated chondrosarcomas, and 2 (6.9%) high-grade spindle cell sarcomas. A false positive MRI diagnosis of skip metastasis was made in 4 cases, 3 enchondromata and one focal nodular marrow hyperplasia. CONCLUSION: The current study has documented the incidence of skip metastases in common types of high-grade primary bone sarcoma. The possibility of false positive skip metastases has also been highlighted.

The current status of MRI in the pre-operative assessment of intramedullary conventional appendicular osteosarcoma.

Osteosarcoma is the commonest primary malignant bone tumour in children and adolescents, the majority of cases being conventional intra-medullary high-grade tumours affecting the appendicular skeleton. Treatment is typically with a combination of neo-adjuvant chemotherapy, tumour resection with limb reconstruction and post-operative chemotherapy. The current article reviews the role of magnetic resonance imaging (MRI) in the pre-operative assessment of high-grade central conventional osteosarcoma.

The role of imaging in differentiating low-grade and high-grade central chondral tumours.

Chondrosarcoma is a malignant cartilage matrix-producing tumour. Those arising de novo are called primary chondrosarcomas and are the second commonest primary malignant bone tumours. Numerous types of primary chondrosarcoma exist, namely conventional central (intramedullary), periosteal (juxta-cortical), clear cell, mesenchymal, and dedifferentiated. The biologic aggressiveness, prognosis and thus management of chondrosarcoma are dependent on the histological sub-type and grade. Accurate pre-operative diagnosis is therefore essential in determining management and outcome which requires a multidisciplinary approach taking into account clinical features, imaging findings and histopathology. In this review, we present the pertinent multimodality imaging features which aid in the differentiation of low-grade and high-grade conventional central chondrosarcoma.

British Thyroid Association 2014 classification ultrasound scoring of thyroid nodules in predicting malignancy: Diagnostic performance and inter-observer agreement.

OBJECTIVES: To assess the inter-observer agreement amongst five observers of differing levels of expertise in applying the British Thyroid Association (2014) guidelines for ultrasound scoring of thyroid nodules (BTA-U score) in the management of thyroid cancer, and to assess the U-score diagnostic performance in predicting malignancy. METHOD: A total of 73 consecutive patients were included over a two-year period (July 2012 to July 2014), after referral to a tertiary head and neck oncology centre for ultrasound plus fine needle aspiration and cytology. Our five observers retrospectively and independently reviewed static ultrasound images on PACS and scored the thyroid nodules according to BTA-U classification. The observers were blinded to each other's scoring, cytology and histology results. Either the Kappa-statistic or intra-class correlation was used to assess the level of inter-observer agreement, plus agreement between the radiological and cytological diagnoses. The diagnostic performance of U-scoring for predicting final histological diagnosis was assessed with sensitivity, specificity, positive and negative predictive values. RESULTS: A Kappa-value of 0.73 (95% CI: 0.68-0.77) confirmed substantial inter-observer agreement amongst the five observers. All 17 histology confirmed malignant nodules were correctly classified as potentially malignant by all observers. The sensitivity and negative predictive value of BTA-U score in detecting and predicting malignancy were 100%, whereas the specificity and positive predictive values were 34% and 32%, respectively. CONCLUSIONS: There is good inter-observer agreement in using the BTA-U score amongst different observers at differing levels of expertise. Adhering to BTA-U scoring can potentially achieve 100% sensitivity in selecting malignant nodules for sampling.