Tumour metastasis at the site of a previous epidural catheter

Epidural analgesia can provide excellent pain relief but can cause a number of rare, serious complications. These complications include epidural abscess, epidural haematoma and permanent neurological injury.The patient in this case report developed a metastasis in the vertebra and epidural space at the site of recent epidural catheterisation. This was a debilitating, life-threatening complication which may or may not have been directly related to the use of the epidural catheter. To our knowledge a direct link between epidural catheterisation and tumour metastasis has not been reported previously

Thermo optical response of photonic crystal cavities operating in the visible spectral range

In this paper we study thermo-optical effects in gallium phosphite photonic crystal cavities in the visible. By measuring the shift of narrow resonances we derive the temperature dependency of the local refractive index of gallium phosphide in attoliter volumina over a temperature range between 5 K and 300 K at a wavelength of about 605 nm. Additionally, the potential of photonic crystal cavities for thermo-optical switching of visible light is investigated. As an example we demonstrate thermo-optical switching with 13 dB contrast.Comment: 13 pages, 9 figure

Rotterdam Criteria for Sentinel Node (SN) Tumor Burden and the Accuracy of Ultrasound (US) -Guided Fine-Needle Aspiration Cytology (FNAC): Can US-Guided FNAC Replace SN Staging in Patients With Melanoma?

Purpose Sentinel node (SN) status is the most important prognostic factor for overall survival (OS) for patients with stage I/II melanoma, and the role of the SN procedure as a staging procedure has long been established. However, a less invasive procedure, such as ultrasound (US) -guided fine-needle aspiration cytology (FNAC), would be preferred. The aim of this study was to evaluate the accuracy of US-guided FNAC and compare the results with histology after SN surgery was performed in all patients. Patients and Methods Four hundred consecutive patients who underwent lymphoscintigraphy subsequently underwent a US examination before the SN procedure. When the US examination showed a suspicious or malignant pattern, patients underwent an FNAC. Median Breslow thickness was 1.8 mm; mean follow-up was 42 months (range, 4 to 82 months). We considered the US-guided FNAC positive if either US and/or FNAC were positive. If US was suggestive of abnormality, but FNAC was negative, the US-guided FNAC was considered negative. Results US-guided FNAC identified 51 (65%) of 79 SN metastases. Specificity was 99% (317 of 321), with a positive predictive value of 93% and negative predictive value of 92%. SN-positive identification rate by US-guided FNAC increased from 40% in stage pT1a/b disease to 79% in stage pT4a/b disease. US-guided FNAC detected SN tumors more than 1.0 mm in 86% of cases, SN tumors of 0.1 to 1.0 mm in 46% of cases, and SN tumors less than 0.1 mm in 23% of cases. Estimated 5-year OS rates were 92% for patients with negative US-guided FNAC results and 51% for patients with positive results. Conclusion US-guided FNAC of SNs is highly accurate. Up to 65% of the patients with SN-positive results in our institution could have been spared an SN procedure