2b Laryngoscope, 126:1260-1266, 2016.

Reoperative thyroid surgery is still challenging even for skilled surgeons, and is associated with a higher incidence of complications, such as hypoparathyroidism and recurrent laryngeal nerve (RLN) palsy. Displacement of the RLN, scar tissue from previous neck surgery and difficulty in maintaining good hemostasis are risk factors in reoperations. The prevalence of RLN injury in reoperative thyroid surgery ranges as high as 12.5% for transient injury and up to 3.8% for permanent injury. Bilateral paresis can also occur during reoperations, and is a dangerous complication influencing the quality of life, sometimes requiring tracheostomy. RLN identification is the gold standard during thyroidectomy, and the use of intraoperative neuromonitoring (IONM) can be a valuable adjunct to visual identification. This technique can be used to identify the RLN and the external branch of the superior laryngeal nerve (EBSLN), both of which are standardized procedures. The aim of this review was to evaluate the use of intermittent neural monitoring of the RLN in surgery for recurrent goiter, and to assess the prevalence of RLN injury while using IONM reported in the current literature.

In the last two decades microRNAs have received great attention in research because of their ability to regulate gene expression. Many studies have shown that defects in different microRNA molecules are linked to many diseases; however, their contribution towards thyroid disease has not been fully explored. Herein, we present a short review of the present state of knowledge on microRNAs, such as their origin, their biogenesis and biological function, as well as their differential expression in papillary thyroid carcinoma. Dysregulated microRNA has been closely linked to thyroid dysfunction and oncogenicity leading to this type of thyroid cancer. The effects of Single Nucleotide Polymorphisms in microRNA are also discussed with respect to papillary thyroid carcinoma.MicroRNAs (miRNA, miR) are a class of endogenous noncoding RNA molecules. Mature miRNAs are short, singlestranded RNA molecules ranging from 18 to 22 nucleotides in length (1). These molecules play a substantial role in the regulation of gene expression, through the induction of translational repression or silencing effects by complementary binding to target mRNAs (2-4). They may also act as tumor suppressor genes and oncogenes (5). Although miRNAs constitute only 3% of the human genome, it is believed that these molecules altogether regulate more than half of the protein-coding genes. Noteworthy, one single miRNA can alter the expression of hundreds of different transcripts (6). MiRNAs are expressed in a tissue-specific fashion (7) and can be found, apart from tissues, also in blood as components of serum, plasma, mononuclear cells and in other body fluids (i.e. urine, semen, saliva, tears, ascitic fluid, amniotic fluid and breast milk) (8, 9). Circulating miRNA molecules are very stable in the blood plasma and serum because they are incorporated in microparticles, such as exosomes and apoptotic bodies (10,11). Biochemical analyses have revealed that miRNA is resistant to RNase activity as well as to extreme acidic and alkaline pH and temperature (12, 13). Biogenesis of microRNAsBriefly, biogenesis of miRNA is initiated by the generation of non-coding primary miRNA (pri-miRNA) transcripts ( 14). MiRNA is first transcribed as pri-miRNA by RNA polymerase II in the nucleus and then, split into precursor microRNA molecules (pre-miRNA) (15). Next, pre-miRNA is transported through exportin 5 (XPO5) to the cytoplasm where it is processed by the Dicer RNase III enzyme, to form mature miRNA (16,17). Mature miRNAs can promote or inhibit mRNA translation and degradation by targeting with precision complementary sequences in 3'UnTranslated Regions (3'UTR) (14,18). In this way, miRNAs modulate different cellular pathways and can be used as therapeutic means to treat pathological conditions, such as cancer (19). Discovery of microRNAsThis novel class of small regulatory RNAs were first described in 1993 by Lee et al. in Caenorhabditis elegans (20). Since their discovery and original description in the 90s, the number of miRNA sequences deposited in the microRNA da...

Background Papillary thyroid microcarcinoma (PTMC) generally is a cancer with excellent prognosis, but the term “cancer” sounds severe and harsh, which can elicit emotional and physical responses from patients. To eliminate the word “cancer,” the term noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was introduced. However, not all PTMCs can be classified as NIFTP. Sometimes, very aggressive PTMC cases might be observed. Some authors suggest that one of the risk factors for poor prognosis is lymph node metastasis. The aim of the study was to evaluate some clinicopathological features of PTMC as the risk factors for lymph node metastasis. Material and methods We performed a retrospective chart review and selected 177 patients with PTMC. To analyze the cases with potentially aggressive behavior, we enrolled PTMC patients with lymph node metastases (pN1, central, and/or lateral) and evaluated some of their clinicopathological features. Results The logistic regression analysis results demonstrated significantly higher rates of multifocal or bilateral tumor occurrence in the PTMC patients with pN1 than in the patients with pN0 ( P < 0.0001 for both). In addition, the occurrence of thyroid tumors with sizes above 0.5 cm was a significant risk factor for lymph node metastasis ( P < 0.0001). The results of the ROC analyses showed that the presence of multifocal or bilateral tumors and tumor sizes above 0.5 cm were significant predictors of lymph node metastasis ( P < 0.0001 for all). Conclusions Multifocal and bilateral PTMC tumors with diameters above 0.5 cm should be treated aggressively as “true cancer” and might benefit from lymph node dissection. Unifocal PTMC tumors with diameters equal to or below 0.5 cm may be treated less aggressively.

BackgroundThe most appropriate surgical procedure for multinodular goiter (MNG) remains under debate. Incidental thyroid carcinoma (ITC) is often identified on histopathological examination after thyroidectomy performed for presumed benign MNG.Aim of the studyThe aim of the study was to determine the value of radical surgery for MNG patients considering the prevalence of ITC diagnosed postoperatively.Materials and MethodsWe conducted retrospective analysis of the medical records of 2,306 patients surgically treated for MNG between 2008 and 2013 at one center. None of the patients presented with any suspicion of malignancy, history of familial thyroid cancer, multiple endocrine neoplasia syndrome or previous head or neck radiation exposure.ResultsAmong the 2,306 MNG patients, ITC was detected in 49 (2.12%) (44 women and 5 men, with average ages of 52.2 (21–79) and 55.6 (52–62), respectively). Papillary thyroid carcinoma was significantly more frequently observed than other types of ITC (p<0.00001). Among the MNG patients, 866 (37.5%) underwent total/near total surgery, 464 (20.1%) received subtotal thyroidectomy, and 701 (30.3%) received the Dunhill operation. The remaining 275 (11.9%) patients underwent a less radical procedure and were classified as "others." Among the 49 (100%) patients with ITC, 28 (57.1%) underwent radical surgery. Another 21 (42.9%) patients required completion surgery due to an insufficient primary surgical procedure. A total of 21 (2.42%) patients in the total/near total surgery group were diagnosed with ITC, as well as 16 (2.48%) in the subtotal thyroidectomy group and 12 (1.71%) in the Dunhill operation group; 21 (100%), 4 (25%) and 3 (25%) of these patients, respectively, underwent radical surgery; thus, 0 (0%), 12 (75%) and 9 (75%) required completion surgery. The prevalence rates of ITC were comparable between the radical and subtotal surgery groups (2.42% and 3.44%, respectively, p = 0.4046), and the prevalence was higher in the radical surgery group than in the Dunhill operation group (2.42% and 1.71%, respectively, p = 0.0873). A significant difference was observed between the group of patients who underwent total/near total surgery, among whom all of the patients with ITC (100%) received primary radical surgery, and the groups of patients who received the subtotal and Dunhill operations, among whom only 25% of the patients with ITC in each group received primary radical surgery (p<0.0001).ConclusionsMore radical procedures for MNG result in a lower risk of reoperation for ITC. The prevalence of ITC on postoperative histopathological examination should determine the extent of surgery in MNG patients. In the future, total/near total thyroidectomy should be considered for MNG patients due to the increased prevalence of ITC to avoid the necessity for reoperation.