Increased prediction of right nonrecurrent laryngeal nerve in thyroid surgery using preoperative computed tomography with intraoperative neuromonitoring identification.

BACKGROUND: A nonrecurrent laryngeal nerve (NRLN) is a rare but potentially serious anatomical variant. Although the incidence is reported to be 0.3% to 1.3%, it carries a much higher risk of palsy during thyroid surgery. The objective of this study is to investigate the usefulness of computed tomography (CT) for preoperative identification and intraoperative neuromonitoring identification (IONM) of NRLN in thyroid cancer patients. METHODS: The preoperative neck CT scans from 1,574 patients who needed thyroid surgery were examined. Absence of the brachiocephalic artery (BCA) and the presence of arteria lusoria were defined as positive with NRLN. Systematic intraoperative neuromonitoring (IONM) was also carried out for these 1,574 patients to localize and identify NRLN. A negative electromyography (EMG) response from lower vagal stimulation but a positive EMG response from the upper position indicated the occurrence of an NRLN. RESULTS: Nine NRLN (0.57%) were intraoperatively identified out of the 1,574 patients, and no patient with a NRLN showed preoperative clinical symptoms related to NRLN. Prior to the operation, surgeons identified only seven suspected NRLN cases based on identification of arteria lusoria. But a review of CT scans revealed that all cases could be identified by vascular anomalies. All patients were successfully detected at an early stage of operation using intraoperative neuromonitoring (IONM). Postoperative vocal cord function was normal in all patients. CONCLUSIONS: CT of the neck is a reliable method for predicting NRLN before thyroid cancer surgery. However, some image features can be easily missed. Neurophysiology helps the surgeon to identify the NRLNs more precisely. Combining the two evaluation methods may decrease the incidence of nerve palsy, especially in cases of NRLN. Considering that CT is expensive, requires an X-ray, and achieves less information than ultrasound (US) concerning thyroid nodules, we suggest that applying US and IONM is more reasonable.

[Pathologic and X-ray features of primary malignant fibrous histiocytoma of bone--a report of 16 cases].

BACKGROUND & OBJECTIVE: Malignant fibrous histiocytoma (MFH) is a common soft tissue tumor, which rarely occur in the skeleton. Its histological origin still remains controversial. This study was to investigate the pathologic and X-ray features of primary MFH of bone, and provide reference for imaging diagnosis. METHODS: Clinical data and X-ray images of 16 MFH patients, treated from Jan. 1982 to Jun. 2002 in the First Affiliated Hospital of Soochow University, were analyzed retrospectively. RESULTS: Pathologic manifestations of the patients were malignant multinucleated giant cells, pleomorphic and bizarre form of the tumor cells, and wheel-spoke arrangement of the fibroblast-like cells. Pathologically, the tumor tissue was consisted of various kinds of cells, which were mainly fibroblasts and histiocytes. The principal X-ray manifestations included solitary osteolytic changes, cortical expansion around the tumor, the penetration of the cortex with soft tissue mass formation, slight periosteal reaction and pathologic fracture. CONCLUSION: The diagnosis of MFH mainly depends on pathologic examination and X-ray manifestations.