[Primary myxoid mediastinal liposarcoma]. / Liposarcome myxoïde primitif du médiastin.

Mediastinal liposarcomas (LPS) are rare tumours. We report a case of primary myxoid LPS in a 22-year-old woman suffering from cough, dyspnoea on exercise and asthenia for 3 weeks. Thoracic MRI showed a large tumour on the right side. After neoadjuvant chemotherapy, a complete resection was performed, followed by adjuvant thoracic irradiation. Eighteen months after the diagnosis, no sign of recurrence was detected. Mediastinal LPS include a heterogeneous group of bulky tumours, the progression of which depends on the histological type. The prognosis is dominated by the operability of the tumour. Adjuvant therapies are not established.

[Immunohistochemistry in ophthalmic pathology: applications and limitations]. / L'immunohistochimie en anatomie pathologique ophtalmologique: intérêt et limites.

We evaluate the applications of immunohistochemistry (IHC) in ophthalmic cytology and pathology. The principles of the techniques used in IHC are described. Recent improvements are highlighted, such as the polymeric labeling two-step method, tyramine signal amplification, rabbit monoclonal antibodies, and labeled nanocrystals. The results of the immunohistochemical methods are collected in bacterial and viral diseases and in tumors of the eye and its adnexa, the pathology of which varies greatly. The results in lymphomas, melanomas, and palpebral tumors were more details for practical reasons. There are widespread applications of IHC in ophthalmic pathology, extending from viral ocular and general diseases to the diagnosis of tumors. In some conditions, this technique needs to be associated with molecular biology investigations. Automation helps establish standard protocols, but IHC is a multistep diagnostic method requiring proper selection, fixation, processing, and staining procedures. From a general standpoint, good communication between pathologists and ophthalmologists is the best guarantee of satisfying results.

Long-term evaluation of motor function following intraneural injection of ropivacaine using walking track analysis in rats.

BACKGROUND: There is a paucity of data regarding neurologic function following nerve injury. Our objective was the long-term evaluation of motor function following intraneural injection of ropivacaine in rats using the sciatic function index (SFI), derived from walking track analysis. METHODS: Rats were randomly assigned to one of four groups of 13 animals each. A needle was inserted under magnification into the left sciatic nerve and 0.2 ml of normal saline, formalin 15%, ropivacaine 0.2 or 0.75% were injected intraneurally. The right side was sham operated. Walking track analysis was performed the day before and on days 1, 4, 7, 11, 15, 18, 21, and 67 following intraneural injection. At the end of the experiment (day 67) a semi-quantitative evaluation of neuropathologic changes was performed by three independent observers. RESULTS: Animals treated with saline and ropivacaine (0.2 and 0.75%) had no detectable impairment of motor function at any time point. In contrast, rats treated with formalin had a complete loss of motor function immediately after the intraneural injection, which persisted until day 21 and returned to normal by day 67. Important histopathologic changes (score=2) with excellent inter-observer agreement were seen only in the group treated with formalin. This applied to both axonal degeneration and Schwann cell density evaluations. CONCLUSIONS: These findings suggest that intraneural injections of ropivacaine at concentrations routinely used in clinical practice appear to have no deleterious effect on sciatic nerve motor function in this experimental rat model.