Alberto Rinaldi Ceroni

Disruptive mitochondrial DNA mutations in complex I subunits are markers of oncocytic phenotype in thyroid tumors

Oncocytic tumors are a distinctive class of proliferative lesions composed of cells with a striking degree of mitochondrial hyperplasia that are particularly frequent in the thyroid gland. To understand whether specific mitochondrial DNA (mtDNA) mutations are associated with the accumulation of mitochondria, we sequenced the entire mtDNA in 50 oncocytic lesions (45 thyroid tumors of epithelial cell derivation and 5 mitochondrion-rich breast tumors) and 52 control cases (21 nononcocytic thyroid tumors, 15 breast carcinomas, and 16 gliomas) by using recently developed technology that allows specific and reliable amplification of the whole mtDNA with quick mutation scanning. Thirteen oncocytic lesions (26%) presented disruptive mutations (nonsense or frameshift), whereas only two samples (3.8%) presented such mutations in the nononcocytic control group. In one case with multiple thyroid nodules analyzed separately, a disruptive mutation was found in the only nodule with oncocytic features. In one of the five mitochondrion-rich breast tumors, a disruptive mutation was identified. All disruptive mutations were found in complex I subunit genes, and the association between these mutations and the oncocytic phenotype was statistically significant (P = 0.001). To study the pathogenicity of these mitochondrial mutations, primary cultures from oncocytic tumors and corresponding normal tissues were established. Electron microscopy and biochemical and molecular analyses showed that primary cultures derived from tumors bearing disruptive mutations failed to maintain the mutations and the oncocytic phenotype. We conclude that disruptive mutations in complex I subunits are markers of thyroid oncocytic tumors.

Transient hypoparathyroidism following thyroidectomy : A prospective study and multivariate analysis of 604 consecutive patients

Objectives The purpose of this study was to identify the risk factors for postoperative transient hypoparathyroidism in a group of patients undergoing thyroid surgery. Study Design A prospective study was conducted on 604 patients undergoing thyroid surgery. Subjects and Methods Gender, final diagnosis, extent of resection, biology of pathology, intrathoracic involvement, surgery for recurrent multinodular goiter, and presence and number of parathyroid glands in a surgical specimen were analyzed as risk factors for postoperative transient hypoparathyroidism. The chi-square test and a logistic regression analysis were applied. RESULTS: On logistic regression analysis, only the extent of surgery constituted an independent variable for transient hypoparathyroidism (P = 0.001). Conclusion The extent of surgery to central and/or lateral neck lymph nodes is responsible for a high rate of transient hypoparathyroidism owing to a high probability of unplanned parathyroidectomy or parathyroid gland devascularization.

Conservative Management of Vestibular Schwannomas : An Effective Strategy

Objectives: Stimulated by the availability of a larger sample of patients and a longer follow‐up period, we update our experience with conservative management of vestibular schwannomas.

Supracricoid partial laryngectomies after radiation failure: A multi‐institutional series

Radiation therapy (RT) is one of the gold standard treatments for early laryngeal cancer, and total laryngectomy is still the most applied surgical procedure after failure. Selected recurrences can be managed by supracricoid partial laryngectomies (SCPLs).

Small acoustic neuromas: monitoring the growth rate by MRI.

Summary In a proportion of small acoustic neuroma patients, monitoring with magnetic resonance imaging shows no volumetric increase of tumour size over the years. The object of the study was to identify some indications for the clinical choice between immediate surgery (with the related risks) and watchful waiting. We performed a retrospective study of 47 non-surgically-treated patients affected by acoustic neuroma and monitored by gadolinium-enhanced MRI between January 1990 and February 1999. Six clinical variables (tumour size, sex, age, initial symptoms, ABR pattern and duration of the symptoms) were examined by univariate analysis. Chi-square test and variance analysis were performed to evaluate the statistical significance. In 30/47 (63.8%) cases, no growth was observed during the entire period of follow-up. In the remaining 17/47 (36.2%) patients, a volumetric increase was detected, most often within the first year of observation. The clinical factors examined did not significantly correlate with growth. Despite the relatively short period of observation, we believe that immediate surgery does not need to be considered mandatory for small acoustic neuromas, even in young patients. However the irregular behaviour of the tumour underlines the importance of monitoring with MRI at least once a year.

The value of neurostimulation and intraoperative nerve monitoring of inferior laryngeal nerve in thyroid surgery

Objective: To determine the accuracy of neurostimulation with laryngeal palpation (NSLP) and intraoperative neuromonitoring (IONM) to predict the postoperative function of recurrent laryngeal nerve (RLN) in thyroid surgery. Study Design: Historical cohort study. Subjects and Methods: A retrospective case control study with 993 patients. The control group (799 patients with 1450 nerves at risk) included patients who underwent NSLP and the case group (194 patients with 354 nerves at risk) consisted of those who underwent NSLP in association with IONM. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and accuracy were calculated for NSLP and IONM, with nerve palsy as the target outcome. Results: A significant difference in nerve injury between the case and the control group (P = 0.31) was not observed. The presence or absence of laryngeal twitch (LT) (P < 0.0001) and the acoustic response to electrical stimulation (P = 0.003) were significantly associated with nerve function at the end of the surgery. Conclusion: Our results indicate that NSLP is a safe and reliable intraoperative method of RLN monitoring. Moreover our data confirm that IONM is not a helpful tool to reduce the rate of palsy in thyroid surgery.

Minimally invasive nonendoscopic thyroidectomy.

OBJECTIVES: Minimal-access thyroid surgery, using various techniques, is increasingly being reported. The present study reviews our experience with thyroid surgery using a minimally invasive approach (MIT). STUDY DESIGN: Between October 2002 and December 2004, a prospective nonrandomized study of patients undergoing thyroid surgery was performed to evaluate the variables that might condition the indications to minimally invasive nonendoscopic approach. RESULTS: 296 patients underwent thyroid surgery; 46 of these were eligible for MIT through a 2.5- to 3-cm incision. There was one case of transient inferior laryngeal nerve palsy and no postoperative definitive hypoparathyroidism. MIT was converted to conventional thyroidectomy only in two cases. Cosmetic results were considered excellent by all patients. CONCLUSIONS: Minimal-access thyroid surgery is a safe and feasible alternative to conventional thyroid surgery in selected cases. The advantage that this technique offers, in addition to low morbidity, is an improved cosmetic result.

Laryngeal neuromonitoring and neurostimulation versus neurostimulation alone in thyroid surgery: A randomized clinical trial

The aim of this study was to assess a prospective, randomized clinical trial (RCT) comparing neurostimulation with laryngeal palpation (NSLP) of recurrent laringeal nerve (RLN) alone with NSLP associated with laryngeal neuromonitoring (LNM) to evaluate the ability of LNM in reducing the rates of RLN palsy.

Superior semicircular canal dehiscence : A series of 13 cases

Increasingly more detailed imaging techniques have recently highlighted the frequent occurrence of bony labyrinthine dehiscence. Among them, superior canal dehiscence (SCD) has been described in a number of cases presenting different features. Here, we report a series of 13 cases, in which the detection of vestibular evoked myogenic potentials (VEMPs) in response to stimuli of abnormally low intensity as compared to normal responses led us to suspect the presence of a ‘third window effect’. An accurate HRCT investigation allowed the diagnosis of SCD. Anamnestic and symptomatologic differences seem difficult to explain, although in our opinion a dural rupture could be at the basis of the onset of pathologic manifestations after many years of silence of a probably malformative condition.

One-phase management of severe obstructive sleep apnea: Tongue base reduction with hyoepiglottoplasty plus uvulopalatopharyngoplasty

OBJECTIVES: To describe the results of a 1 phase surgical procedure for the treatment of severe obstructive sleep apnea (OSA) attributable to tongue base obstruction. STUDY DESIGN AND SETTING: A retrospective nonrandomized study at S Orsola Malpighi University Hospital of Bologna, Italy. METHODS: Ten male patients affected by severe OSA (mean apnea/hypopnea index [AHI] of 54.7), underwent uvulopalatopharyngoplasty (UPPP) associated with tongue base reduction and hyoepiglottoplasty (TBRHE). The indications to this surgical procedure were based on the presence of hyolingual abnormalities and absence of craniofacial deficiencies determined by preoperative assessment. RESULTS: Mean AHI decreased from 54.7 + 11.5 to 9.4 + 5.4 whereas the mean low SaO2 value went from 77% + 6.2 to 90.7% + 3 and the time of sleep with SaO2 < 90% improved from 53% + 17.2 to 7.3% + 8. The overall success rate was 100%. CONCLUSIONS AND SIGNIFICANCE: TBRHE is an effective and safe treatment in patients with severe OSA attributable to tongue base obstruction and in absence of craniofacial deficiencies.