No abstract

Progress in biotechnology has provided useful tools for tracing proteins involved in thyroid hormone synthesis in vivo. Mono- or polyclonal antibodies are now available to detect on histological sections the Na(+)/I(-) symporter (NIS) at the basolateral pole of the cell, the putative iodide channel (pendrin) at the apical plasma membrane, thyroperoxidase (TPO), and members of the NADPH-oxidase family, thyroid oxidase 1 and 2 (ThOXs), part of the H(2)O(2)-generating system. The aim of this study was to correlate thyroglobulin (Tg) iodination with the presence of these proteins. Tg, T(4)-containing Tg, NIS, pendrin, TPO, ThOXs, and TSH receptor (TSHr) were detected by immunohistochemistry on tissue sections of normal thyroids and various benign and malignant thyroid disorders. Tg was present in all cases. T(4)-containing Tg was found in the adenomas, except in Hurthle cell adenomas. It was never detected in carcinomas. NIS was reduced in all types of carcinomas, whereas it was detected in noncancerous tissues. Pendrin was not expressed in carcinomas, except in follicular carcinomas, where weak staining persisted. TPO expression was present in insular, follicular carcinomas and in follicular variants of papillary carcinomas, but in a reduced percentage of cells. It was below the level of detection in papillary carcinomas. The H(2)O(2)-generating system, ThOXs, was found in all carcinomas and was even increased in papillary carcinomas. Its staining was apical in normal thyroids, whereas it was cytoplasmic in carcinomas. The TSHr was expressed in all cases, but the intensity of the staining was decreased in insular carcinomas. In conclusion, our work shows that all types of carcinomas lose the capacity to synthesize T(4)-rich, iodinated Tg. In follicular carcinomas, this might be due to a defect in iodide transport at the basolateral pole of the cell. In papillary carcinomas, this defect seems to be coupled to an altered apical transport of iodide and probably TPO activity. The TSHr persists in virtually all cases.

The close correlation between the severity of perisinusoidal fibrosis and the daily dose of the retinol intake suggests the existence of a dose-effect relationship.

In comparison with SuperPulse, the UltraPulse carbon dioxide laser made the procedure easier, but did not improve the clinical outcome.

Endoscopic resection of laryngeal tumors is replacing external approaches. One drawback of endoscopic resection is the difficulty of interpretation of histological specimens because of thermal effect of laser on tissues. Our goal is to assess the reliability of frozen section in this setting by comparing its results with those of routine histology. We, retrospectively, reviewed the charts of all consecutive patients, who underwent cordectomies in our institution between January 2000 and 2008, using the CO(2) laser Acublade system (Lumenis, Santa Clara, CA). Age, sex, staging of the tumor, previous treatments, type of cordectomy, frozen section and routine histology results were analyzed. Ninety-seven patients fulfilled the inclusion criteria; 22.7% had severe dysplasia, 54.6% had T1 epidermoid carcinoma, 17.5% had T2 carcinoma and finally 5.2% had T3 carcinoma. We performed type I cordectomy in 36.1% of patients, type II cordectomy in 18.6%, type III cordectomy in 10.3%, type IV cordectomy in 5.2%, type V cordectomy in 28.9% and type VI cordectomy in 1% of patients. Most of the patients did not have any previous treatment. The mean number of margins per surgery was 2. Routine histological examination confirmed frozen section in 94.8% of the interventions. Frozen section is reliable in laser-assisted cordectomies, when performed by an experienced team; it has a high negative-predictive value. It can limit the need, cost and emotional stress of second look surgeries.