Epithelioid schwannoma of the ulnar nerve. Some clinical observations.

The authors describe one case of purely epithelioid schwannoma of the ulnar nerve and discuss the therapeutic management. A 44 year-old man was referred to us for a fusiform, movable mass in the left ulnar nerve and was removed by a wide en bloc excision. Intraoperative nerve action potentials were performed both prior to and following excision of the lesion. Histologically, the tumor was composed of round or polygonal cells arranged in necrotic clusters and anastomosing cords. There were areas of spindle cells. The epithelioid cells were round with abundant cytoplasm. Mitoses were frequent. S100 protein immunoreactivity was present diffusely in tumor cells (both nuclear and cytoplasmic), whereas cytokeratin, NSE, and anti-melanoma reactions gave negative results. After a 13 months, the patient's neurological conditions are excellent and there are no signs of either recurrence or metastasis.

Magnetic resonance imaging findings in piriformis syndrome: a case report.

Piriformis syndrome (PS) is an unusual cause of sciatica that, because of the lack of strict diagnostic criteria, remains a controversial clinical entity. The diagnosis of PS is still primarily clinical because no diagnostic tests have proven to be definitive. We report the case of a 30-year-old woman, affected by a severe scoliosis, who developed a persistent buttock pain resembling that of PS. The clinical suspicion was confirmed by magnetic resonance imaging (MRI) of the pelvis, which showed an enlargement of the left piriformis muscle with an anterior isplacement of the sciatic nerve. The role of MRI in the diagnosis, clinical definition, and therapeutic approach to PS is discussed.

[Magnetic resonance in the assessment of critical points of impingement of the shoulder]. / La risonanza magnetica nella valutazione dei punti critici di attrito della spalla.

Impingement syndrome is caused by a conflictual status between rotator cuff, subacromial bursa and anatomic and functional acro-mioclavicular arch. The clinical signs of this syndrome include pain and functional disability in abduction and extrarotation of the shoulder. This study was aimed at verifying Magnetic Resonance Imaging (MRI) capabilities in showing the critical points of impingement and their incidence. Fifty-four cases of impingement syndrome were studied. The best visualization of functional acromioclavicular arch was obtained using a new study technique. All patients had critical points of impingement. In 65% of cases, acromioclavicular arthritis induced impingement on the supraspinatus tendon and in 35% of cases on the muscle. In 46% of the patients, impingement between coracoacromial ligament, partially thickened in 25% of the cases and totally thickened in 75%, and supraspinatus tendon was observed. In 7% of the whole of shoulders, the acromion had an uncinatus shape. MRI, thanks to its multiplanar imaging, allowed the complete evaluation of the articular structures with complex anatomy. The assessment of different types of impingement points can be considered a valuable approach to the therapeutic stage.

[Technologic advances in magnetic resonance imaging: permanent low-field magnets dedicated to the study of the joints. Clinical results]. / Innovazioni tecnologiche nella Tomografia con Risonanza Magnetica: magneti permanenti con basso campo dedicati allo studio articolare. Risultati clinici.

Magnetic Resonance Imaging (MRI) has had a significant impact on the diagnosis of musculoskeletal conditions. Technologic advances in the last years allowed the development of cost-effective, compact and easy-to-install MR systems. After an early phase to optimize the units, a 14-month multicentric study was performed to define the possible clinical applications of the system. The obtained data are reported by the authors in the present study to assess the diagnostic accuracy of the new MR system for the study of the limbs. The system consists of an 0.2 T permanent unit, weighting 800 Kg, with a built-in radiofrequency shield and 10 mT/m gradients. October, 1992, to February, 1994, 2437 limbs examinations were carried out in patients whose age ranged 5 to 83 years. In 93% of cases, the exam was performed to study one joint, mostly the knee. MR diagnosis was verified in 311 patients, who were subsequently submitted to surgery. Quite satisfying overall results were obtained, particularly in case of knee traumas, comparable to those provided by units with more potentials. The particular structure of the magnet allowed the comfortable management of the pediatric, aged and acute patients. Nevertheless, in 3% of the investigated knee or elbow conditions, the examinations could not be performed due to technical limitations related to magnet size. In addition, the authors believe that a limited field of view (11-16 cm) does not allow accurate staging of the malignant lesions involving soft tissue and bone, which require a wider locoregional staging.

[Acute instability of the shoulder in athletes. The role of magnetic resonance in therapy planning]. / Instabilità acuta della spalla negli atleti. Ruolo della risonanza magnetica nella pianificazione terapeutica.

Magnetic resonance imaging (MRI) of the shoulder was performed to evaluate both the actual role of this technique in the study and staging of acute shoulder instability, and its potentials as diagnostic tool, with particular reference to treatment planning. Seventeen athletes with acute shoulder instability were examined. All MRI examinations, subsequent to plain radiographs, were performed within 48 hours from the traumatic event. After MRI examination, 14 patients underwent physiotherapy (2 cases were subsequently submitted to arthrotomy), and only 3 cases underwent surgical treatment in the acute phase (2 arthrotomies and 1 arthroscopy). These cases, submitted to MRI in the acute phase and subsequently to surgery, showed anterior glenoid labrum involvement with good evidence of associated skeletal lesions (Hill-Sachs lesions in 1); changes in the inferior glenohumeral ligament complex (2 cases) were also observed. In the other examined cases, MRI always provided accurate information on the glenoid labra and the anterior capsular mechanism. When the superior glenohumeral ligament was investigated (9 cases of 17), no alterations were observed. Acting as natural contrast, the presence of joint effusion allows good visualization, on T1-weighted sequences, of the structures involved by the traumatic events. Contrast resolution improvement could be obtained by employing gradient-echo T2 weighted sequences, which proved to be quite valuable for a correct depiction of the lesions involving the inferior glenohumeral ligament complex. In conclusion, MRI can be considered as a valuable diagnostic method for the early evaluation of the acute shoulder instability, since it provides information of the utmost importance for the subsequent therapeutical approach.