Update of cartilaginous tumours according to the WHO classification 2020.

Cartilaginous tumours are a large and heterogeneous group of neoplasms characterised by the presence of a chondroid matrix, with lobular growth and arcuate, ring-like or popcorn-like calcification patterns. MRI shows hyperintensity in T2-weighted sequences and a lobulated or septal relief in postcontrast images. In the WHO 2020 classification, chondral tumours are classified as benign, intermediate or malignant. Despite technological advances, they continue to pose a challenge for both the radiologist and the pathologist, being the main difficulty the differentiation between benign and malignant tumours, which is why they require a multidisciplinary approach. This paper describes the main changes introduced in the 2020 update, describes the imaging characteristics of the main cartilaginous tumours and provides the radiological keys to differentiate between benign and malignant tumours.

Diagnosis of lesions of the acetabular labrum, of the labral-chondral transition zone, and of the cartilage in femoroacetabular impingement: Correlation between direct magnetic resonance arthrography and hip arthroscopy.

OBJECTIVE: To determine the sensitivity and accuracy of direct MR arthrography in the diagnosis of intra-articular lesions associated with femoroacetabular impingement. MATERIAL AND METHODS: We used direct MR arthrography to study 51 patients with femoroacetabular impingement who underwent arthroscopic hip surgery. Surgery demonstrated 37 labral tears, 44 lesions in the labral-chondral transitional zone, and 40 lesions of the articular cartilage. We correlated the findings at preoperative direct MR arthrography with those of hip arthroscopy and calculated the sensitivity, specificity, positive predictive value, negative predictive value, and validity index for direct MR arthrography. RESULTS: The sensitivity and specificity of MR arthrography were 94.5% and 100%, respectively, for diagnosing labral tears, 100% and 87.5%, respectively, for diagnosing lesions of the labral-chondral transition zone, and 92.5% and 54.5%, respectively, for diagnosing lesions of the articular cartilage. The negative predictive value of MR arthrography for lesions of the labral-chondral transitional zone was 100%. MR arthrography accurately defined extensive lesions of the cartilage and the secondary osseous changes (the main factor in poor prognosis), although its diagnostic performance was not so good in small chondral lesions. CONCLUSION: In patients with femoroacetabular impingement, direct MR arthrography can adequately detect and characterize lesions of the acetabular labrum and of the labral-chondral transitional zone as well as extensive lesions of the articular cartilage and secondary osseous changes.

[Primary mesenchymal chondrosarcoma of the mediastinum]. / Condrosarcoma mesenquimal primario en el mediastino.

Cartilaginous lesions of the mediastinum are quite rare and primary cartilage forming tumors arising within the mediastinum are even more exceptional. Radiologic findings are unspecific. However, certain characteristics can orient the diagnosis. They are presented one mediastinal chondrosarcoma case in adult patient of patho-anatomical diagnosis. The findings described entail chest radiography, computed tomography and magnetic resonance.

[Progression following the embolisation of 100 intracranial arteriovenous malformations]. / Evolución tras la embolización de 100 malformaciones arteriovenosas intracraneales.

INTRODUCTION: We analysed the characteristics, progression and outcomes observed following the embolisation of 100 intracranial arteriovenous malformations (AVM) that were performed in order to achieve complete obliteration of the AVM, the elimination of associated vascular risk factors and also to reduce their size with a view to increasing the effectiveness of later treatments. PATIENTS AND METHODS: The demographic and anatomical characteristics of 110 patients with AVM were analysed over a period of 13 years, and embolisation was performed in 100 of them. In all, 203 embolisation sessions were carried out with an average of 3 embolisations per patient. Of the 100 AVM that were embolised, 36 were AVM which were treated by embolisation with no later therapy, 48 required radiosurgery after the embolisation and the other 16 were submitted to surgery following the embolisation. The type of materials used included liquid adhesive embolic agents (Hystoacryl, Glubran), non-adhesive embolic agents (Onyx) and polyvinyl alcohol particles. Patients were examined clinically and arteriographically. RESULTS: Of the 100 AVM that were embolised, complete eradication was accomplished with just embolisation in 27 cases of AVM (27%). Of the 48 AVM in which radiosurgery was carried out at a later date, the average rate of obliteration was 78% and of the 16 AVM in which surgery was carried out some time later, the average rate of obliteration was 70%. Of the 100 AVM that were embolised, some residue remained in 16 cases. Embolisation eliminated most of the associated vascular risk factors, as can be seen by the fact that associated risk factors disappeared in 28 (65%) out of the 43 AVM with such factors. The morbidity and mortality rates with embolisation were 8% and 2%, respectively. CONCLUSIONS: Embolisation eliminated most of the vascular risk factors, with complete obliteration in 27 cases and size was satisfactorily reduced for later treatment; at the same time, morbidity and mortality rates were acceptable.

[Hypothalamic-infundibular histiocytosis: magnetic resonance findings]. / Histiocitosis hipotálamo-infundibular: hallazgos en resonancia magnética.

INTRODUCTION: We report the magnetic resonance imaging (MRI) of a case of Langerhans cell histiocytosis in the pituitary. Isolated central nervous system involvement is uncommon. CASE REPORT: An eighteen-years old female patient who had an acute onset of central diabetes insipidus because of the Langerhans cell histiocytosis. The MRI evidenced a lesion in the hypothalamic-pituitary axis. The hyperintensity in the posterior pituitary lobe, which is seen in normal subjects on T1-weighted images, was absent. The pituitary stalk was thickened and enhanced homogeneously following contrast administration. During the follow-up, the infundibullar lesion extended to the hypothalamic region and other systemic manifestations appeared. Diagnosis of Langerhans cell histiocytosis was confirmed by lung biopsy. After radiotherapy and chemotherapy, MRI showed regression of the hypothalamic-pituitary lesion. CONCLUSION: The combination of these findings, although nonspecific of Langerhans cell histiocytosis, should nevertheless prompt further studies, including chest films, bone scanning and temporal bone computerized tomography in order to narrow the differential diagnosis.