Temperature-controlled spectrophotometry: a simultaneous analysis of phase transition, thermal degradation and optical properties of semi-transparent composites from 20 °C to 450 °C

So far, optical and effective radiative properties of polymer matrix based composites were investigated at temperatures well below their degradation temperature. At the same time, polymers exhibit temperature dependent physical properties and may undergo structural changes as their temperature raises. In this work, we employ the "Temperature-Controlled Spectrophotometry", a new method enabling to identify simultaneously phase transitions, thermal degradation and radiative properties of semi-transparent composites over a large temperature range. The method consists of measuring simultaneously the normal-normal and the normal-hemispherical transmittances and reflectances of the sample subjected to a laser irradiation with tuneable wavelength while the temperature is rised from room temperature up to 450 °C by means of a CO₂ laser. Physical changes of the sample are identified from the temperature variation of normal-normal transmittance and specular reflectance measurements. Most of the results here are presented at a specific wavelength of 1070 nm but the proposed method is suitable over the semi-transparency spectral domain of the material by changing the wavelength of the probe laser. An inverse method for parameter identification based on normal-hemispherical measurements is employed to determine the transport effective radiative properties of the sample, namely the transport extinction coefficient and the transport scattering albedo from room temperature to 325 °C.

Optical properties of oakwood in the near-infrared range of semi-transparency

The spectral absorption and scattering properties of oakwood are retrieved from the measurements of both the normal-hemispherical reflectance and transmittance in the visible and near-infrared ranges of semi-transparency. We employ two alternative methods for the radiative transfer in wood samples: the modified two-flux approximation and the high-order discrete ordinate method. The modifications of both methods take into account the effect of total internal reflection at both surfaces of the wood samples. The analytical approximate solution of the first method gives very accurate results for the absorption coefficient, but the transport scattering coefficient of wood appeared to be systematically underestimated. Fortunately, this error is between 7% and 12%, and that is acceptable for the estimates. The oakwood samples of four different thicknesses were used in the experiments. The effect of the wood cell orientation appears to be insignificant and can be observed in the reflectance from optically thin samples only. There is a considerable decrease in the transport scattering coefficient of oakwood with the wavelength. This effect is explained by a predominant contribution of micron-sized longitudinal pores in oakwood. The latter is used to develop an approximate theoretical model of scattering based on the rigorous solution for arbitrary-oriented cylindrical pores. The model suggested is in good agreement with the experimental data.

Endocrine tumors associated with the vagus nerve

The vagus nerve (cranial nerve X) is the main nerve of the parasympathetic division of the autonomic nervous system. Vagal paragangliomas (VPGLs) are a prime example of an endocrine tumor associated with the vagus nerve. This rare, neural crest tumor constitutes the second most common site of hereditary head and neck paragangliomas (HNPGLs), most often in relation to mutations in the succinate dehydrogenase complex subunit D (SDHD) gene. The treatment paradigm for VPGL has progressively shifted from surgery to abstention or therapeutic radiation with curative-like outcomes. Parathyroid tissue and parathyroid adenoma can also be found in close association with the vagus nerve in intra or paravagal situations. Vagal parathyroid adenoma can be identified with preoperative imaging or suspected intraoperatively by experienced surgeons. Vagal parathyroid adenomas located in the neck or superior mediastinum can be removed via initial cervicotomy, while those located in the aortopulmonary window require a thoracic approach. This review particularly emphasizes the embryology, molecular genetics, and modern imaging of these tumors.

MANAGEMENT OF ENDOCRINE DISEASE: Outcome of adrenal sparing surgery in heritable pheochromocytoma

The management of hereditary pheochromocytoma has drastically evolved in the last 20 years. Bilateral pheochromocytoma does not increase mortality in MEN2 or von Hippel-Lindau (VHL) mutation carriers who are followed regularly, but these mutations induce major morbidities if total bilateral adrenalectomy is performed. Cortical sparing adrenal surgery may be proposed to avoid definitive adrenal insufficiency. The surgical goal is to leave sufficient cortical tissue to avoid glucocorticoid replacement therapy. This approach was achieved by the progressive experience of minimally invasive surgery via the transperitoneal or retroperitoneal route. Cortical sparing adrenal surgery exhibits <5% significant recurrence after 10 years of follow-up and normal glucocorticoid function in more than 50% of the cases. Therefore, cortical sparing adrenal surgery should be systematically considered in the management of all patients with MEN2 or VHL hereditary pheochromocytoma. Hereditary pheochromocytoma is a rare disease, and a randomized trial comparing cortical sparing vs classical adrenalectomy is probably not possible. This lack of data most likely explains why cortical sparing surgery has not been adopted in most expert centers that perform at least 20 procedures per year for the treatment of this disease. This review examined recent data to provide insight into the technique, its indications, and the results and subsequent follow-up in the management of patients with hereditary pheochromocytoma with a special emphasis on MEN2.

Preoperative imaging for focused parathyroidectomy: making a good strategy even better

OBJECTIVE

Surgical treatment for primary hyperparathyroidism (pHPT) has undergone a major paradigm shift during the last decades from bilateral cervicotomy with four-gland neck exploration to image-guided focused approaches. The primary objective of the present study was to compare the performances of parathyroid scintigraphy (PS), parathyroid ultrasonography (US), and the combination of both procedures for guiding a focused approach on the basis of modified interpretation criteria.

METHODS

Data from 199 patients operated for apparent sporadic pHPT and evaluated with US and PS using dual-isotope (123)I/(99m)Tc-sestamibi planar pinhole and single-photon emission computed tomography (SPECT) acqusitions were evaluated.

RESULTS

A total of 127 patients underwent a focused approach and the remainder had bilateral cervicotomy. In 42 cases, a focused approach was not performed due to the absence of concordant results between US and PS for a single-gland abnormality. Four patients had persistent disease and three had recurrent disease. A localizing preoperative PS had a sensitivity of 93.3%, positive predictive value of 85.8%, negative predictive value of 73.0%, and accuracy of 83.4% for predicting uniglandular disease. Additional SPECT images accurately localize posterior adenomas that are often missed by US. Compared with PS, US had a lower sensitivity (P<0.01). Our imaging protocol also enabled diagnosis of multiglandular disease in 60.6%.

CONCLUSIONS

PS using a highly sensitive dual-tracer subtraction method is the most accurate technique for directing a focused approach. PS could be sufficient for directing a focused approach in the presence of a negative US in two major circumstances: posterior locations due to acquired ectopia that could be missed by US, and previous history of thyroidectomy due to interpretation difficulties.

Diagnosis and preoperative imaging of multiple endocrine neoplasia type 2: current status and future directions

Multiple endocrine neoplasia type 2 (MEN2) is a rare autosomal dominant syndrome caused by mutations in the RET protooncogene and is characterized by a strong penetrance of medullary thyroid carcinoma (all subtypes) and is often accompanied by pheochromocytoma (MEN2A/2B) and primary hyperparathyroidism (MEN2A). The evaluation and management of MEN2-related tumours is often different from that of sporadic counterparts. This review article provides an overview of clinical manifestations, diagnosis and surgical management of MEN2 patients. This review also presents applications of the most up-to-date imaging modalities to MEN2 patients that are tightly linked to the clinical management and aims to guide physicians towards a rationale for the use of imaging prior to prophylactic thyroidectomy, initial surgery and reoperations for persistent/recurrent disease. This review also concludes that, in the near future, it is expected that these patients will indeed benefit from newly developed positron emission tomography approaches which will target peptide receptors and protein kinases. Identification of MEN2-specific radiopharmaceuticals will also soon arise from molecular profiling studies. Furthermore, subtotal (cortical-sparing) adrenalectomy, which is a valid option in MEN2 for avoiding long-term steroid replacement, will benefit from an accurate estimation through imaging of differential adrenocortical function.

Quality of life is modestly improved in older patients with mild primary hyperparathyroidism postoperatively: results of a prospective multicenter study

BACKGROUND

The objectives of this study were to evaluate, in mild primary hyperparathyroidism (pHPT) patients, the quality of life (QoL) using the SF-36 questionnaire before and after parathyroidectomy and to detect preoperatively patients who benefit the most from surgery. Most pHPT patients present a mild pHPT defined by calcemia ≤11.4 mg/dL. For these patients, there is debate about whether they should be managed with surveillance, medical therapy, or surgery.

METHODS

A prospective multicenter study investigated QoL (SF-36) in patients with mild pHPT before and after parathyroidectomy in four university hospitals. Laboratory results and SF-36 scores were obtained preoperatively and postoperatively (3, 6, and 12 months).

RESULTS

One hundred sixteen patients were included. After surgery, the biochemical cure rate was 98%. Preoperatively, the mental component summary and the physical component summary (PCS) were 38.69 of 100 and 39.53 of 100, respectively. At 1 year, the MCS and the PCS were 41.29 of 100 and 42.03 of 100. The subgroup analysis showed a more significant improvement in patients < 70 years and with calcemia ≥10.4 mg/dL. Postoperative PCS was correlated with age and preoperative PCS: variation = 32.11 - 0.21 × age - 0.4 × preoperative PCS. Men did not improve their MCS postoperatively. Only women with a preoperative MCS <43.6 of 100 showed postoperative improvement.

CONCLUSIONS

This study showed, in patients with mild pHPT, an improvement of QoL 1 year after parathyroidectomy. Patients <70 years and with calcemia ≥10.4 mg/dL had a more significant improvement.

Contemporary review of large adrenal tumors in a tertiary referral center

BACKGROUND

Large adrenal tumors (LATs, ≥6 cm) are uncommon and associated with malignancy in 25% of cases. Their surgical management remains debatable. The aim of the present report was to evaluate the current incidence, nature and management of LAT.

PATIENTS AND METHODS

We carried out a retrospective review of LATs managed in a tertiary referral center (2002-2011).

RESULTS

Eighty-one patients were included (out of a total of 750 with adrenal tumors, 11%). Nine patients had no surgical intervention (11%). Fifty-two LATs were malignant (64%): adrenocortical carcinoma (44%), metastasis (27%) and pheochromocytoma (21%). Patients with malignant tumors exhibited a poorer 5-year overall survival than those with benign tumors (53.4% versus 96.3%, p=0.001). Disease-related mortality was approximately 60%, 29% and 0% for those with metastasis, adrenal carcinoma and malignant pheochromocytoma, respectively. The recurrence rate was the same for the three malignant sub-groups (30%).

CONCLUSION

LATs are rare and more frequently malignant than previously reported. Some are benign and do not require for surgical intervention. Surgical indication and approach should be tailored for each patient.

Surgery for 'asymptomatic' mild primary hyperparathyroidism improves some clinical symptoms postoperatively

OBJECTIVE AND BACKGROUND

Most primary hyperparathyroidism (pHPT) patients do not conform to the guidelines for parathyroidectomy established by an international panel of specialists and have a mild pHPT. This group is typically defined as 'asymptomatic'. The primary aim of this study was to determine symptom improvement in this 'asymptomatic' group after parathyroidectomy. Secondly, we aimed to create a preoperative clinical score predicting postoperative symptom resolution.

DESIGN

A prospective nonrandomized study included patients with mild pHPT.

METHODS

A questionnaire (22 items) was given to 'asymptomatic' patients preoperatively and at 3, 6, and 12 postoperative months. A logistic regression was performed to create a preoperative clinical score.

RESULTS

One hundred and sixteen patients were included. Postoperatively, HPT was resolved in 98% of patients. Twelve of 22 nonspecific symptoms were improved at 1 year. Subgroups analysis showed a greater improvement in patients <70 years and those with a serum calcium level ≥2.6 mmol/l preoperatively. A clinical score, based on age and five symptoms, was established to predict the clinical improvement after surgery in mild pHPT patients with a positive predictive value of 81%.

CONCLUSION

Patients with asymptomatic pHPT have clinical improvement of their symptoms postoperatively even after 1 year. Younger patients and those with higher preoperative calcium levels show the best improvement.

Lithium-associated hyperparathyroidism: surgical strategies in the era of minimally invasive parathyroidectomy

BACKGROUND

Lithium remains an effective treatment of bipolar affective disorder. The long-term use of lithium is associated with an alteration in parathyroid function that may culminate in hyperparathyroidism. The long-term effects of lithium use are variable due to its complex effects on calcium homeostasis and bone metabolism, and as a consequence the indications for surgery remain poorly defined. The optimal surgical strategy for lithium-associated hyperparathyroidism in the era of minimally invasive surgery is also the subject of debate. The aim of the present study was to evaluate the variable findings of lithium-associated parathyroid disease.

METHODS

A retrospective review was performed of patients undergoing parathyroid surgery presenting with lithium-associated hyperparathyroidism from July 1999 until July 2009 at the university hospital La Timone, Marseille, and from October 2005 to July 2009 at Hammersmith Hospital, Imperial College, London. Fifteen patients underwent surgery for lithium-associated hyperparathyroidism. Clinical data including patient demographics, duration of lithium use, clinical manifestations of hyperparathyroidism, indications for surgery, and biochemical parameters preoperatively and postoperatively were reviewed. Preoperative imaging, the surgical procedure performed, operative findings, and histopathology were also analyzed.

RESULTS

All 15 patients had preoperative imaging: sestamibi scanning showed that 10 patients had localized single-gland disease, 1 had multiple hot spots, and 4 had a negative scan. Ultrasonography demonstrated a single abnormal gland in 8 patients and multiple enlarged glands in 1 patient; the test was negative in 6. As a consequence of concordant preoperative imaging a minimally invasive approach (endoscopic or a focused lateral approach) was adopted in 3 patients. Focused surgery demonstrated an enlarged hyperplastic gland in 3 cases and resulted in normocalcemia in the immediate postoperative period. However, one patient has a serum calcium at the upper limit of normal and elevated parathyroid hormone (PTH) levels, suggestive of possible recurrence of disease at 15 months follow-up. One patient has permanent hypoparathyroidism. In those patients who had open procedures, final histology showed hyperplastic multiglandular disease in 10 patients (83.3%) of patients and single-gland disease in 2 patients (16.7%). None of these patients show evidence of recurrence at follow-up.

CONCLUSIONS

Lithium hyperparathyroidism is predominantly a multiglandular disease characterized by asymmetrical hyperplasia that is frequently associated with misleading or discordant localization studies. Bilateral neck exploration is therefore recommended in order to minimize the risk of disease recurrence.

Expression of somatostatin receptors, dopamine D₂ receptors, noradrenaline transporters, and vesicular monoamine transporters in 52 pheochromocytomas and paragangliomas

While somatostatin receptors (sst), through somatostatin-radiolabeled analogs, are used, mainly in second line, in the diagnosis and treatment of pheochromocytomas (PCC) and paragangliomas (PGL), the clinical significance of dopamine receptor subtype 2 (D₂) in PCC/PGL is unknown. Indeed, radiolabeled dopamine (DA) analogs such as fluorine 18 ((18)F)-DA, used for positron emission tomography in PCC localization, are mainly correlated to the presence of noradrenaline transporter (NAT) and vesicular monoamine transporters (VMAT) but not to D₂. The aim of this study was to quantitate D₂ and sst expression in 52 PCC/PGL and to compare it with that of 35 gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Quantitative RT-PCR of sst(1-3) and sst₅, D₂, NAT, VMAT1/2 was performed in all tumors, while immunohistochemistry analysis of sst₂ and D₂ was performed in seven tumors. D₂ mRNA was expressed in all PCC/PGL. Mean expression was significantly higher in PCC/PGL than in GEP-NETs (4.8 vs 0.5 copy/copy β-glucuronidase (Gus)). sst₂ and sst(1) were expressed in most PCC/PGL, with sst(2)-dominant expression (mean mRNA: 1.6 vs 0.4 copy/copy β-Gus). sst₂ expression level was similar to that of GEP-NETs, whereas sst₅ expression level was significantly lower (0.12 vs 0.78 copy/copy β-Gus). Our study evidenced strong D₂ mRNA expression in PCC and for the first time in PGL. PCC/PGL express sst₂ mRNA at levels similar to those of GEP-NETs. New drugs can target ssts and D₂ more efficiently than current somatostatin analogs. Moreover, transporters like NAT and VMAT1/2, could be co-targeted with sst, as a basis of new radionuclide compounds in the imaging and treatment of these tumors.

Comparison of [¹¹¹In]pentetreotide-SPECT and [¹⁸F]FDOPA-PET in the localization of extra-adrenal paragangliomas: the case for a patient-tailored use of nuclear imaging modalities

AIMS AND METHODS

The aim of this prospective study was to compare the diagnostic value of [¹⁸F]FDOPA-PET and [¹¹¹In]pentetreotide-SPECT somatostatin receptor scintigraphy (SRS) in patients with nonmetastatic extra-adrenal paragangliomas (PGLs). Twenty-five consecutive unrelated patients who were known or suspected of having nonmetastatic extra-adrenal PGLs were prospectively evaluated with SRS and [¹⁸F]FDOPA-PET. ¹³¹I-MIBG and [¹⁸F]FDG-PET were added to the work-up in patients with a personal or familial history of PGL, predisposing mutations, abdominal PGLs, metanephrine hypersecretion and abdominal foci on SRS and/or [¹⁸F]FDOPA-PET.

RESULTS

SRS correctly detected 23/45 lesions of which 20 were head or neck lesions (H&N) and 3 were abdominal lesions. [¹⁸F]FDOPA-PET detected significantly more lesions than SRS (39/45, P < 0·001). Both SRS and ¹⁸F-DOPA-PET detected significantly more H&N than abdominal lesions (66·7% vs 20%, P = 0·003 and 96·7% vs 67%, P = 0·012, respectively). In two patients with the succinate dehydrogenase D (SDHD) mutation, [¹⁸F]FDOPA-PET missed five abdominal PGLs which were detected by the combination of SRS, [¹³¹I]MIBG and [¹⁸F]FDG-PET. A lesion-based analysis using a forward stepwise logistic regression model demonstrates that size ≤ 10 mm (P = 0·002) and abdominal lesions (P = 0·031) were independently associated with "[¹⁸F]FDOPA-PET diagnosis only". In turn, a previous history of surgery and/or the presence of germline mutation was associated with lower lesion size (P = 0·001).

CONCLUSIONS

The sensitivity of SRS for localizing parasympathetic PGLs is lower than originally reported, and [¹⁸F]FDOPA-PET is better than SRS for localizing small lesions. SRS should be replaced by [¹⁸F]FDOPA-PET as the first-line imaging procedure in H&N PGL, especially in patients at risk of multifocal disease (predisposing mutations and or previous history of surgery).

Shear wave elastography: a new ultrasound imaging mode for the differential diagnosis of benign and malignant thyroid nodules

CONTEXT

Elastography uses ultrasound (US) to assess elasticity. Shear wave elastography (SWE) is a new technique that estimates tissue stiffness in real time and is quantitative and user independent.

OBJECTIVES

The aim of the study was to assess the efficiency of SWE in predicting malignancy and to compare SWE with US.

DESIGN

Ninety-three patients and 39 control subjects were included in the study. Predictive value of SWE was assessed by correlation between elasticity, US parameters, and histology. Elasticity index (EI) was first analyzed alone. Scores have been constructed with echographic parameters, i.e. vascularity, hypoechogenicity, and microcalcifications (Score 1=US Score), and with the same parameters plus EI (Score 2=US+SWE Score). For statistical analysis, univariate and multivariate analysis and receiver operating characteristic curves were used.

RESULTS

A total of 146 nodules from 93 patients were analyzed. Twenty-nine nodules (19.9%) were malignant. Mean (±sd) EI was 150±95 kPa (range, 30-356) in malignant nodules vs. 36±30 (range, 0-200) kPa in benign nodules (P<0.001, Student's t test). For a positive predictive value of at least 80%, characteristics of tissue elasticity (cutoff, 65 kPa) were: sensitivity=85.2%, and specificity=93.9%. Characteristics of the US Score were: sensitivity=51.9% [95% confidence interval (CI), 33.1; 70.7], and specificity=97% (95% CI, 93.6; 1). Characteristics of the US+SWE Score were: sensitivity=81.5% (95% CI, 66.9; 96.1), and specificity=97.0% (95% CI, 93.6; 1).

CONCLUSION

Promising results have been obtained with SWE. This technique may be applied to multinodular goiters. Larger prospective studies are needed to confirm these results and to define the respective places of SWE, US, and FNA.

Minimal access surgery - thyroid and parathyroid

The concept of surgical invasiveness cannot be limited to the length or to the site of the skin incision. It must be extended to all structures dissected during the procedure. Therefore, MIT or MIP should properly be defined as operations through a short and discrete incision that permits direct access to the thyroid or parathyroid gland, resulting in a focused dissection.Parathyroid glands are particularly suitable for minimally invasive surgery as most parathyroid tumors are small and benign. MIP are performed through a limited or discrete incision when compared to classic open transverse cervical incision and are targeted on one specific parathyroid gland. The concept of these limited explorations is based on the fact that 85% of patients will have single-gland disease. MIP must be proposed only for patients with sporadic hyperparathyroidism in whom a single adenoma has been clearly localized by preoperative imaging studies.The minimal access approaches to the thyroid gland may be broadly classified into three groups: the mini-open lateral approach via a small incision, minimally invasive video-assisted thyroidectomy via the midline and various endoscopic techniques. Endoscopic extracervical approaches have the main advantage of leaving no scar in the neck but cannot reasonably be described as minimally invasive as they require more dissection than conventional open surgery.Initially the indications for MIT were a solitary thyroid nodule of less than 3 cm in diameter in an otherwise normal gland. Today, MIT are also proposed in patients with small nodular goiters, Graves's diseases and low risk papillary thyroid cancers. Some concern remains about the radicality of MIT in this latter group but preliminary results are comparable to those of conventional surgery both in terms of I-131 uptake and serum thyroglobuline levels.Demonstrating the advantages of MIT and MIP over conventional surgery is not easy. Main complications, such as nerve injury, hypoparathyroidism, or hemorrhage, are the same as in conventional surgery. Several studies comparing conventional surgery with minimally invasive techniques using a cervical access have shown a diminution of postoperative pain, and better cosmetic results with minimally invasive techniques. MIP and MIT seem overall to be an advance but only randomized studies will demonstrate the real benefit.

Could primary hyperparathyroidism-related hypercalcemia induce hypercalcitoninemia?

AIMS

To determine if primary hyperparathyroidism (pHPT) per se may be responsible of hypercalcitoninemia. pHPT induces chronic hypercalcemia that should be expected to be a potential stimulatory pathway of calcitonin (CT) secretion and to cause hypercalcitoninemia.

METHOD

We studied relationships between CT and pHPT-related chronic hypercalcemia in 122 patients aged 25-83 years who underwent parathyroid surgery. CT, calcium and PTH plasma levels were measured in all patients preoperatively. CT was measured by a current immunometric assay specific of mature CT monomer.

RESULTS

Of our 122 patients with pHPT-related hypercalcemia, 120 (98.4%) had normal CT values of less than 10 pg/ml and two (1.6%) exhibited a mildly increased CT above 10 pg/ml (11 and 12 pg/ml, respectively). We evidenced no relationship between CT and calcium level or PTH level.

CONCLUSIONS

Chronic pHPT-related hypercalcemia per se does not cause hypercalcitoninemia. The finding of pHPT concomitant with high CT levels should raise suspicion of multiple endocrine neoplasia type 2A.

Iodine biokinetics and radioiodine exposure after recombinant human thyrotropin-assisted remnant ablation in comparison with thyroid hormone withdrawal

CONTEXT

A few prospective studies have evaluated the use of recombinant human TSH (rhTSH) for radioiodine remnant ablation.

OBJECTIVE

Our objective was to compare the effects of the both TSH regimens on iodine biokinetics in the thyroid remnant, dosimetry, and radiation protection.

DESIGN

We conducted a prospective randomized study.

MATERIALS AND METHODS

Eighty-eight patients were enrolled for radioiodine ablation to either the hypothyroid or rhTSH arms. A whole-body scan was performed at 48 and 144 h after therapy. Dose rates were assessed at 24, 48, and 144 h. Urinary samples were obtained during the first 48 h. Thyroglobulin was assessed before and after therapy. Iodine biokinetics in the remnants were calculated from gamma-count rates. Radiation-absorbed dose was calculated using OLINDA software. Exposure estimation was based on a validated model.

RESULTS

The effective half-life in the remnant thyroid tissue was significantly longer after rhTSH than during hypothyroidism (P = 0.01), whereas 48-h (131)I uptakes and residence times were similar. After therapy, thyroglobulin release (a marker of cell damage) was lower in the rhTSH arm. The mean total-body effective half-life and residence time were shorter in patients treated after rhTSH. Residence time was also lower for the colon and stomach. Absorbed dose estimates were lower in the rhTSH arm for the lower large intestine, breasts, ovaries, and the bone marrow. Dose rates at the time of discharge were lower in the rhTSH group with a reduction in cumulative radiation exposure to contact persons.

CONCLUSIONS

In comparison with thyroid hormone withdrawal, rhTSH is associated with longer remnant half-life of radioactive iodine while also reducing radiation exposure to the rest of the body and also to the general public who come in contact with such patients.

Tumor protein p53-induced nuclear protein (TP53INP1) expression in medullary thyroid carcinoma: a molecular guide to the optimal extent of surgery?

BACKGROUND

Medullary thyroid cancer (MTC) is characterized by early regional lymph node metastasis, the presence of which represents a critical obstacle to cure. At present no molecular markers have been successfully integrated into the clinical care of sporadic MTC. The present study was designed to evaluate TP53INP1 expression in MTC and to assess its ability to guide the surgeon to the optimal extent of surgery performed with curative intent.

METHODS

Thirty-eight patients with sporadic MTC were evaluated. TP53INP1 immunoexpression was studied on embedded paraffin material and on cytological smears.

RESULTS

TP53INP1 was expressed in normal C cells, in C-cell hyperplasia, and in 57.9% of MTC. It was possible to identify two groups of MTC according to the proportion of TP53INP1 expressing tumor cells: group 1 from 0% to <50% and group 2 from 50% to 100% of positive cells. Patients with a decreased expression of TP53INP1 (group 1) had a lower rate of nodal metastasis (18.8% versus 63.4% in group 2; P = 0.009), with only minimal lymph node involvement per N1 patient (2.7% of positive lymph nodes versus 22.9%; P < 0.001) and better outcomes (100% of biochemical cure versus 55.5%; P < 0.001). Patients with distant metastases were only observed in group 2. Cytological samples exhibit similar results to their embedded counterparts.

CONCLUSIONS

TP53INP1 immunoexpression appears to be a clinical predictor of lymph node metastasis in MTC. The evaluation of TP53INP1 expression may guide the extent of lymph node dissection in the clinically node-negative neck. These findings require prospective validation.

Mild hypercalcitoninaemia and sporadic thyroid disease

Background

Not operating on patients with mild hypercalcitoninaemia (MHCT) and sporadic thyroid disease carries the risk of omitting curative surgery for medullary thyroid cancer, but systematic surgery would result in unnecessary treatment of benign pathology. This study reviewed the management of MCHT and non-hereditary thyroid disease in one centre.

Methods

MCHT was defined as an increase in basal and stimulated calcitonin levels not exceeding 30 and 200 pg/ml respectively. Over 15 years, 125 patients who presented with MCHT and sporadic thyroid disease were followed. Surgery was indicated only if there were local pressure symptoms or suspicious histomorphological changes in solitary nodules.

Results

Fifty-five patients underwent total thyroidectomy and 18 unilateral total lobectomy. Histological examination revealed medullary microcarcinoma in six patients (two women and four men). C-cell hyperplasia was found in 54 patients (74 per cent) and 13 (18 per cent) harboured no C-cell pathology. Calcitonin levels stabilized after lobectomy and became undetectable following thyroidectomy. They normalized during follow-up in a third of patients who did not have surgery.

Conclusion

Not all patients with MHCT and sporadic thyroid disease require surgery.

Limited value of 18F-F-DOPA PET to localize pancreatic insulin-secreting tumors in adults with hyperinsulinemic hypoglycemia

CONTEXT

Fluorine-18-L-dihydroxyphenylalanine positron emission tomography (18F-FDOPA PET) imaging is increasingly used in the workup of neuroendocrine tumors. It has been shown to be an accurate tool in the diagnosis of congenital hyperinsulinism, but limited information is available on its value in adult disease. OBJECTIVE, PATIENTS, AND DESIGN: The objective of this study was to review our experience with 18F-FDOPA PET imaging in six consecutive patients with hyperinsulinemic hypoglycemia (HH) (four solitary insulinomas, one diffuse beta-cell hyperplasia, one malignant insulinoma). 18F-FDOPA uptake was also evaluated in 37 patients (43 procedures) without HH or other pancreatic neuroendocrine tumors, which acted as a control group.

RESULTS

Using visual analysis, 18F-FDOPA-PET proved positive in only one case (a multiple endocrine neoplasia type 1 related insulinoma). In diffuse beta-cell hyperplasia, the pancreatic uptake was similar to controls. In the patient with liver metastases, the extent of disease was underestimated. The pancreatic uptake was not statistically different between controls and hyperinsulinemic patients. The main limitation for identifying insulinomas or beta-cell hyperplasia in adults appears to be to the 18F-FDOPA uptake and retention in the whole pancreas. This drawback is potentially circumvented in focal hyperplasia in newborns due to a lower aromatic amino acid decarboxylase expression in the extralesional pancreatic parenchyma.

CONCLUSIONS

18F-FDOPA PET is of limited value in localizing pancreatic insulin secreting tumors in adult HH. Our results contrast with the referential study and require further analysis.

Quality of life changes and clinical outcomes in thyroid cancer patients undergoing radioiodine remnant ablation (RRA) with recombinant human TSH (rhTSH): a randomized controlled study

BACKGROUND

Recombinant human TSH (rhTSH) has become the modality of choice for radioiodine remnant ablation (RRA) in low-risk thyroid cancer patients.

AIMS AND METHODS

The aims of the present prospective randomized study were to evaluate the impact of TSH stimulation procedure (hypothyroidism vs. rhTSH) on quality of life (QoL) of thyroid cancer patients undergoing RRA and to evaluate efficacy of both procedures. L-T4 was initiated in both groups after thyroidectomy. After randomization, L-T4 was discontinued in hypothyroid (hypo) group and continued in rhTSH group. A measure of 3.7 GBq of radioiodine was given to both groups. The functional assessment of chronic illness therapy-fatigue (FACIT-F) was administered from the early postoperative period to 9 months. Socio-demographic parameters, anxiety and depression scales were also evaluated (CES-D, BDI and Spielberger state-trait questionnaires). At 9 months, patients underwent an rhTSH stimulation test, diagnostic (131)I whole body scan (dxWBS) and neck ultrasonography.

RESULTS

A total of 74 patients were enrolled for the study. There was a significant decrease in QoL from baseline (t0) to t1 (RRA period) in the hypothyroid group with significant differences in FACIT-F TOI (P < 10(-3)), FACT-G total score (P = 0.005) and FACIT-F total score (P = 0.003). By contrast, QoL was preserved in the rhTSH group. In the multivariate analysis, FACIT-TOI changes were only affected by the modality of TSH stimulation performed for RRA. From 3 to 9 months, changes of QoL scales and subscales were no longer statistically different in both groups of patients. Based on serum rhTSH-stimulated Tg alone (Tg < 0.8 microg/l, BRAHMS Tg Kryptor), no difference in ablation success was observed between rhTSH and hypothyroidism groups, 91.7% and 97.1%, respectively. A higher rate of persistent thyroid remnants was observed in the rhTSH arm, although in most cases uptake was < 0.1% and of no clinical significance.

CONCLUSIONS

rhTSH preserves QoL of patients undergoing RRA with similar rates of ablation success compared to hypothyrodism. However, there is a wide heterogeneity in the clinical impact of hypothyroidism.

What is the evidence for endoscopic thyroidectomy in the management of benign thyroid disease?

Background

Endoscopic thyroidectomy (ET) is a demanding surgical technique in which dissection of the gland is entirely performed with an endoscope, in a closed area maintained by insufflation or mechanical retraction. ET by direct cervical approach (anterior or lateral) is minimally invasive, but ET using an extracervical access (chest wall, breast, or axillary) is not. No technique seems to be universally accepted yet. This review was designed to clarify the existing evidence for performing endoscopic thyroid resections in the management of benign thyroid nodules.

Methods

A database search was conducted in PubMed and Embase from which summaries and abstracts were screened for relevant data, matching our definition. Publications were further assessed and assigned their respective levels of evidence. Additional data derived from our own unit’s experience with endoscopic thyroidectomy were included.

Results

Thirty mainly retrospective cohort studies have been published in which morbidity, such as unilateral vocal cord palsy, is poorly evaluated. ET takes from 90 to 280 minutes for lobectomy by cervical access and total thyroidectomy by chest wall approach, respectively. Cosmetic outcome in extracervical approach is less troubled by size of the resected specimen compared with direct cervical approach. Extracervical approach avoids a neck scar but implies invasiveness in terms of dissection and postoperative discomfort. Long-term cosmetic outcome comparisons with conventional thyroidectomy have not been published.

Conclusions

Currently it is not possible to recommend the application of ET based on evidence. Reported complications stress the importance of advanced endoscopic skills. ET should only be offered to carefully selected patients and, therefore, a high volume of patients requiring thyroid surgery is needed. Superiority of endoscopic to conventional thyroidectomy has yet to be demonstrated. Possible advantages of endoscopic thyroid techniques and our patient’s desire for the highest cosmetic outcome possible justify further development of ET in expert hands of endocrine surgeons.

Safety of laparoscopic adrenalectomy in patients with large pheochromocytomas: a single institution review

BACKGROUND

Laparoscopic adrenalectomy is the procedure of choice for small adrenal tumors, but some concerns have been voiced when this approach is adopted for larger tumors and pheochromocytomas. The aim of this study was to examine the results of the laparoscopic resection of large pheochromocytomas.

METHODS

A retrospective review of adrenalectomies performed for adrenal pheochromocytomas>6 cm in diameter. We compiled and analyzed the early operative complications, histologic findings, and cure rates with a minimum of 1 year of follow-up after surgery.

RESULTS

From 1996 to 2005, a total of 445 laparoscopic adrenalectomies were performed in our institution using the anterolateral transperitoneal approach. From this series we identified 18 procedures for pheochromocytomas with an average diameter on imaging of 78.2 mm (range 60-130 mm). All patients were rendered safe with a standard departmental protocol involving calcium-channel blockade initiated at least 2 weeks prior to surgery. The average peak intraoperative blood pressure was 187 mmHg. Capsular disruption occurred in two cases. One patient required an intraoperative blood transfusion due to intraoperative blood loss. No immediate conversions to an open procedure were required, but one patient underwent a delayed laparotomy for hematoma formation. Histologically, four of the adrenal tumors displayed evidence of vascular invasion. Biochemical cure was achieved in all patients after a median follow-up of 58 months (16-122 months).

CONCLUSIONS

Laparoscopic adrenalectomy appears to be a safe and effective approach for large pheochromocytomas when no preoperative or intraoperative evidence of local invasion is present.

The role of 18F-FDOPA and 18F-FDG-PET in the management of malignant and multifocal phaeochromocytomas

BACKGROUND

(18)F-DOPA has emerged as a promising tool in the localization of chromaffin-tissue-derived tumours. Interestingly, phaeochromocytomas (PHEO) are also FDG avid.

AIM AND METHODS

The aim of this study was to retrospectively evaluate the results of (18)F-FDOPA and/or (18)F-FDG-PET in patients with PHEO and paragangliomas (PGLs) and to compare the outcome of this approach with the traditional therapeutic work-up. Nine patients with non-MEN2 related PHEO or PGL were evaluated. At the time of the PET studies, the patients were classified into three groups based on their clinical history, conventional and SPECT imaging. The groups were malignant disease (n = 5, 1 VHL), apparently unique tumour site in patients with previous surgery (n = 1, SDHB) and multifocal tumours (n = 3, 1 VHL, 1 SDHD). (18)F-FDOPA and (18)F-FDG-PET PET/CT were then performed in all patients.

RESULTS

PET successfully identified additional tumour sites in five out of five patients with metastatic disease that had not been identified with SPECT + CI. Whilst tumour tracer uptake varied between patients it exhibited a consistently favourable residence time for delayed acquisitions. (18)F-FDOPA uptake (SUVmax) was superior to (18)F-FDG uptake in cases of neck PGL (three patients, four tumours). If only metastatic forms and abdominal PGLs were considered, (18)F-FDG provided additional information in three cases (two metastatic forms, one multifocal disease with SDHD mutation) compared to (18)F-FDOPA.

CONCLUSIONS

Our results suggest that tumour staging can be improved by combining (18)F-FDOPA and (18)F-FDG in the preoperative work-up of patients with abdominal and malignant PHEOs. (18)F-FDOPA is also an effective localization tool for neck PGLs. MIBG however, still has a role in these patients as MIBG and FDOPA images did not completely overlap.

Does 18F-FDG PET/CT add diagnostic accuracy in incidentally identified non-secreting adrenal tumours?

PURPOSE

The widespread use of high-resolution cross-sectional imaging such as computed tomography (CT) and magnetic resonance imaging (MRI) for the investigation of the abdomen is associated with an increasing detection of incidental adrenal masses. We evaluated the ability of (18)F-fluorodeoxyglucose positron emission tomography to distinguish benign from malignant adrenal masses when CT or MRI results had been inconclusive.

METHODS

We included only patients with no evidence of hormonal hypersecretion and no personal history of cancer or in whom previously diagnosed cancer was in prolonged remission. PET/CT scans were acquired after 90 min (mean, range 60-140 min) after FDG injection. The visual interpretation, maximum standardised uptake values (SUVmax) and adrenal compared to liver uptake ratio were correlated with the final histological diagnosis or clinico-radiological follow-up when surgery had not been performed.

RESULTS

Thirty-seven patients with 41 adrenal masses were prospectively evaluated. The final diagnosis was 12 malignant, 17 benign tumours, and 12 tumours classified as benign on follow-up. The visual interpretation was more accurate than SUVmax alone, tumour diameter or unenhanced density, with a sensitivity of 100% (12/12), a specificity of 86% (25/29) and a negative predictive value of 100% (25/25). The use of 1.8 as the threshold for tumour/liver SUVmax ratio, retrospectively established, demonstrated 100% sensitivity and specificity.

CONCLUSION

FDG PET/CT accurately characterises adrenal tumours, with an excellent sensitivity and negative predictive values. Thus, a negative PET may predict a benign tumour that would potentially prevent the need for surgery of adrenal tumours with inconclusive conventional imaging.

Tomoscintigraphy Improves the Determination of the Embryologic Origin of Parathyroid Adenomas, Especially in Apparently Inferior Glands: Imaging Features and Surgical Implications

Identification of the embryologic origin of hyperfunctioning parathyroid adenomas in primary hyperparathyroidism (PHPT) could determine the most suitable approach for minimally invasive surgery. The aim of this study was to prospectively evaluate the reliability of a new, combined protocol for the preoperative localization and determination of the embryologic origin of parathyroid adenomas.

METHODS

Anterior dual-isotope ((123)I/(99m)Tc-sestamibi) static planar imaging followed by tomoscintigraphy (SPECT acquisition) centered over the 140-keV photopeak (combined protocol) was performed on 35 consecutive patients with sporadic PHPT. On the basis of anatomic considerations, adenomas were classified as superior (P4 derived) if they were located above the isthmus or posterior to the thyroid on SPECT images, despite their apparently middle to inferior position, and as inferior (P3 derived) if the foci were located in inferior and anterior positions or along the thyrothymic tract. Parathyroid ultrasonography was performed on all patients.

RESULTS

A total of 36 adenomas were removed: 34 solitary adenomas and 1 double adenoma (for totals of 19 P3-derived and 17 P4-derived adenomas). Pinhole subtraction imaging, SPECT, and ultrasonography sensitivities for detecting adenomas were 86%, 78%, and 77%, respectively. False-positive contralateral images were observed only with ultrasonography (3 cases). Positive SPECT results were associated with higher gland weights. Thirteen glands were identified by SPECT as posterior glands, despite their apparently inferior position, and were removed through an appropriate lateral endoscopic approach. Eleven (85%) of these glands had a P4 origin. Only 2 corresponded to large P3-derived adenomas (>2 g).

CONCLUSION

By reclassifying apparently inferior adenomas as P4-derived adenomas prolapsed behind the thyroid gland, SPECT provides information about the most suitable surgical approach for avoiding recurrent laryngeal nerve injury. Additional pinhole images should increase the detection of small adenomas. The combined protocol offers both advantages.

Intraoperative diagnosis and treatment of parathyroid cancer and atypical parathyroid adenoma

Background

Distinction of parathyroid cancer from atypical parathyroid adenoma (APA) at operation is difficult. The aim of this study was to determine whether parathyroid cancer and APA have different operative findings and long-term outcomes.

Methods

A retrospective review was undertaken of patients with suspicious or malignant parathyroid tumours treated between 1974 and 2005. Parathyroid cancer was defined as a lesion with vascular or tissue invasion, and APA as a neoplasm with broad fibrous bands, trabecular growth, mitosis and nuclear atypia.

Results

Twenty-seven patients with suspicious or malignant parathyroid tumours were identified. After histological review, parathyroid cancer was confirmed in 11 patients (group 1) and 16 tumours were classified as APA (group 2). The clinical presentation and operative findings of the two types of tumour were indistinguishable. At initial surgery, seven patients in group 1 underwent en bloc resection, and four had parathyroidectomy. Four of the seven patients who had en bloc resection had recurrences. No recurrences were observed in the other seven patients in group 1 at a median follow-up of 65 months. In group 2, eight patients had en bloc resection and eight had parathyroidectomy; no patient had recurrence at a median follow-up of 91 months.

Conclusion

Operative findings cannot distinguish APA from parathyroid cancer reliably. Without evidence of macroscopic local invasion, the value of en bloc resection at initial surgery remains debatable.

Prospective evaluation of quality of life (SF-36v2) and nonspecific symptoms before and after cure of primary hyperparathyroidism (1-year follow-up)

BACKGROUND

Only a minority of patients with primary hyperparathyroidism (pHPT) present with the "classic" symptoms. Most patients have numerous nonspecific symptoms. The aim of this study was to evaluate patients' quality of life and nonspecific symptoms before and after cure for pHPT.

METHODS

This prospective, multicentric study, which took place from May 2003 to September 2004, included 100 patients. Six academic departments of Endocrine Surgery in France participated in the study: the University of Angers, Limoges, Nancy, Nantes, Marseille, and Poitiers. Only cured patients were included. All patients were given preoperative and postoperative questionnaires (the SF-36v2 Health Survey) at 3, 6, and 12 months to evaluate quality of life and nonspecific symptoms.

RESULTS

Preoperatively, the main nonspecific symptoms included the following: anxiety (89%); muscular, bone, or join pain (87%); abdominal distention (82%); forgetfulness (81%); headaches (81%); and mood swings (79%). Quality of life was significantly improved at 3 and 6 months (P < .05). At 1 year postoperatively, statistically significant improvement (P < .05) persisted in all 8 domains of the SF-36v2. At 1 year after parathyroidectomy, 5 symptoms remained significantly improved: appetite loss, weight loss, thirst, headache, and nausea.

CONCLUSIONS

Operative cure of primary hyperparathyroidism significantly improves quality of life and nonspecific symptoms for at least 1 year.

Isolated adrenal metastasis: the role of laparoscopic surgery

BACKGROUND

Solitary adrenal metastases (AM) are rare and their management unclear. Surgery, especially laparoscopic adrenalectomy (LA), is debatable in the management of AM. This retrospective study analysed the feasibility and the results of LA for AM.

METHODS

From 1997 to 2003, 16 patients underwent LA for isolated AM. Completeness of resection, postoperative morbidity and follow-up (FU) were recorded.

RESULTS

There were 10 synchronous AM and 6 metachronous AM. Primary tumours included lung cancer (n = 9), melanoma (n = 3), mesothelioma (n = 1), rhabdomyosarcoma (n = 1), colonic adenocarcinoma (n = 1) and renal cell carcinoma (n = 1). Five patients required conversion to an open procedure. Minor complications occurred in three patients. Pathology confirmed the diagnosis of AM. Mean tumour size was 60 (range: 15-110) mm. Nine patients (56%) had complete resections, 3 had positive margins and 4 had incomplete macroscopic resections. Mean observed FU was 25 (range: 1-68) months. Median overall calculated survival was 23 months. Overall 5-year survival was 33% (Kaplan-Meyer). At the end of study, 8 patients were alive with a mean FU of 35 months (3 without evidence of disease). No patient presented with local relapse or port-site metastasis. We did not identify any predictive factors. All patients with incomplete macroscopic resection died within 24 months.

CONCLUSIONS

LA can achieve an acceptable 5-year survival, comparable to open surgery but with better postoperative comfort. It should be considered for AM with the intention of complete resection. It offers the patient the possibility of tumour resection with the benefit of a laparoscopic approach.

Endoscopic lateral approach thyroid lobectomy: safe evolution from endoscopic parathyroidectomy

INTRODUCTION

Endoscopic thyroid surgery has been shown to be feasible. Most minimal access procedures have been performed via a midline approach. Based on our experience of more than 500 endoscopic parathyroidectomies via a lateral approach we have used the same method for thyroid lobectomy.

METHODS

We present our experience of endoscopic thyroid lobectomy via a lateral approach (ETLA) and review of the results over a 1-year period (2004). Inclusion criteria for ETLA were (1) solitary nodule with atypical/suspicious fine-needle biopsy (FNB) or solitary toxic nodule; (2) lesions with a diameter of < 3 cm. Patients with a history of previous neck surgery or radiation exposure were excluded. All patients underwent postoperative vocal cord checks and plasma calcium evaluation.

RESULTS

A total of 742 thyroid procedures were performed during 2004. Among them, 38 patients (5.1%) underwent ETLA. Indications for surgery were suspicious FNB results (36 patients) and a toxic nodule (2 patients). Mean nodule size was 19.2 mm. Mean +/- SD operating time was 102 +/- 27 minutes. All recurrent laryngeal nerves were identified (including one that was nonrecurrent). Of the 38 patients, the superior parathyroid gland was identified in 36 and the inferior parathyroid gland in 33. There were two conversions due to difficulty with the dissection. Two operations were converted because malignancy was diagnosed on frozen section examination. Two patients underwent a delayed completion thyroidectomy when definitive histology necessitated it. There were no permanent operative complications, and all patients were discharged on the first postoperative day.

CONCLUSIONS

ETLA offers excellent intraoperative visualization of the vital structures and is a safe alternative to conventional thyroid lobectomy in selected cases.

Long-term outcome following laparoscopic adrenalectomy for large solid adrenal cortex tumors

INTRODUCTION

Laparoscopic adrenalectomy (LA) is the procedure of choice for small benign adrenal tumors. In the absence of local invasion or metastases, the preoperative diagnosis of an adrenocortical carcinoma (ACC) is difficult, often leaving size as the principal predictor of malignancy. Large tumors are resectable laparoscopically, but the long-term outcome and therefore appropriateness of LA for cortical tumors > 6 cm is not known.

METHODS

We reviewed the LA experience in our institution since its introduction in June 1994. Patients who underwent LA for solid cortical tumors > or = 60 mm in diameter without preoperative or intraoperative evidence of malignancy were reviewed. Follow-up data, including clinical examination, biochemical analysis, and repeat scans, were reviewed for evidence of local or systemic recurrent disease.

RESULTS

Between 1994 and 2004 a total of 462 adrenalectomies were performed, 391 of which were done laparoscopically. Among them, 19 were solid cortical tumors > or = 60 mm in diameter with no overt malignant preoperative or intraoperative characteristics: 9 nonsecreting tumors, 8 Cushing's syndrome tumors (including 2 virilizing variants), 1 virilizing tumor, and 1 aldosteronoma. The mean age of the patients was 49.9 years (range 22-77 years), and the mean tumor size was 69.0 mm (range 60-80 mm). Histology confirmed a cortical adenoma in eight patients, malignant tumors in three, and indeterminate tumors in eight. The mean follow-up was 34 months (range 4-108 months). Two patients died of systemic recurrent disease (liver metastases) at 10 and 19 months, respectively, following surgery; two other patients died 12 and 21 months, respectively following surgery owing to unrelated cardiovascular and cerebrovascular pathology. One patient underwent surgery for local recurrence 54 months after primary surgery; the remaining 14 patients are well with no clinical or radiologic evidence of recurrent disease.

CONCLUSIONS

Laparoscopic adrenalectomy for large solid cortical tumors without pre- or intraoperative evidence of malignancy is not contraindicated, and it is unlikely to have a deleterious effect on long-term outcome. Each case should be considered individually. We provide an algorithm for the approach to adrenocortical tumors > or = 6 cm.

Lifestyle behaviours and components of energy balance as independent predictors of ghrelin and adiponectin in young non-obese women

AIM

Dysregulation of the normal levels of ghrelin, leptin and adiponectin in young non-obese subjects could promote food intake, diabetes and cardiovascular disease in later stages of life. Little information is available on how plasmatic concentrations of these hormones may be influenced by eating habits and/or components of energy balance in a young population, which if known, could facilitate their voluntary regulation.

METHODS

In this cross-sectional study we examined the predictors of fasting plasma ghrelin, adiponectin and leptin in a population of well-characterized young non-obese women (N = 63). Energy intake was assessed by 24-hour dietary recall, resting metabolic rate (RMR) by indirect calorimetry, physical activity energy expenditure (PAEE) by tri-axial accelerometer, physical fitness by VO(2 peak), and eating behaviors by self administrated questionnaire.

RESULTS

Lower RMR and higher HDL-cholesterol were independent predictors of higher plasma ghrelin explaining 17.6% of its variation even after correcting for BMI. Higher total or central fat mass was the only predictor of higher plasma leptin, and no other variable added any power to the prediction equation. Finally, higher energy intake and waist circumference and lower PAEE predicted lower plasma adiponectin in young non-obese women, explaining 43% of the variation in its concentrations even after correcting for total or central fat mass.

CONCLUSION

Components of the energy balance (ie: energy intake and/or expenditure) influence adiponectin and ghrelin circulating levels. That is, higher energy intake and lower physical activity independently predict lower adiponectin concentrations, whereas lower resting metabolic rate independently predicts higher ghrelin levels in young non-obese women. Prospective studies are needed to examine whether circulating concentrations of ghrelin and adiponectin can be voluntarily regulated by lifestyle interventions.

Thyroid surgery: postoperative hematoma--prevention and treatment

BACKGROUND AND AIMS

Postoperative haematoma formation is a fortunately rare but potentially life-threatening complication of thyroid surgery. This paper aims to identify potential aetiological factors, describe surgical techniques and newer haemostatic agents that may be used to minimise the risk of haematoma formation and propose surgical strategies to deal with haematoma formation.

MATERIALS AND METHODS

An extensive literature search as well as own considerable experience in a tertiary referral centre endocrine surgical unit was drawn upon to review this topic.

CONCLUSIONS

Postoperative haematoma may have a multifactorial aetiology. Numerous manoeuvres and surgical haemostatic agents may be employed to minimise the risk of haematoma formation but are no substitute for meticulous haemostasis. In the event of haematoma formation, early surgical re-intervention is strongly advocated with due care given to at risk structures.

[Applied embryology of parathyroid glands]

The article describes the normal structure of the parathyroid glands (PTG) and their development, anomalies of migration in the process of embryogenesis and congenital ectopias of PTG as well as possible supplementary PTG and their congenital ectopias.

Endocrine surgical technique: endoscopic thyroidectomy via the lateral approach

BACKGROUND

Minimal access approaches are increasingly used in endocrine surgery. Several minimal access approaches to the thyroid gland have been described, including a small-incision lateral approach and a video-assisted central approach, but to date no technique has been universally accepted.

METHODS

Benefiting from the experience of more than 500 endoscopic parathyroidectomies via a lateral neck approach, the authors developed an endoscopic thyroidectomy based on the same approach and principles. Patients with solitary nodules smaller than 3 cm in diameter and no history of neck surgery or irradiation were offered this operation. A detailed description of the surgical technique is provided.

RESULTS

Of the 742 thyroidectomies performed in 2004, 38 (5.1%) were endoscopic thyroidectomies. The mean nodule size was 22-mm (range, 7-47-mm), and the mean operating time was 99 min (range, 64-150-min). In all cases, the recurrent laryngeal nerve was preserved intact, and the superior and inferior parathyroids were identified, respectively, in 36 and 33 of the 38 patients. Two patients required conversion to an open cervicotomy. All patients were discharged the day after surgery.

CONCLUSIONS

The described endoscopic lateral approach combines the coherence of the minimal access lateral approach and the benefits of fiberoptic magnification. It is a safe and effective technique in the hands of an appropriately trained surgeon.

[Abrikossoff tumor of the proximal esophagus misdiagnosed as a thyroid nodule]

The diagnosis of thyroid nodules is straightforward and rarely mistaken. We present a case of a paraesophageal granular cell tumor, discovered incidentally during surgery for what it was diagnosed as a suspicious thyroid nodule by ultrasound and FNA. Complete resection was achieved without disruption of the esophageal mucosa. A terminal branch of the recurrent laryngeal nerve had to be resected en bloc with the tumor. Morphological and immunohistochemical diagnosis was established postoperatively. A review of the literature is presented.

A single-institution 25-year review of true parathyroid cysts

BACKGROUND

Parathyroid cysts (PCs) are rare, and their origin is a subject of debate. They have been described as either functional, causing hyperparathyroidism, or non-functional in eucalcaemic patients.

PATIENTS AND METHODS

We have performed a 25-year departmental review of PCs. Features studied included the clinical presentation and intra-operative findings, and a histological review was performed. Cases of cystic degeneration of parathyroid adenomas and pseudocystic change were excluded.

RESULTS

Over 25 years, 22,009 thyroidectomies and 2,505 parathyroidectomies were performed in our department. Amongst these, 38 non-functional PCs were documented in 37 patients. The mode of presentation included incidental findings on routine chest x-ray, compressive symptoms or an asymptomatic palpable neck mass. Aspiration was the initial treatment in 14 patients and was curative in 10 of these. Four out of 14 patients underwent surgical procedures for recurrence of the cyst that occurred 6 to 48 months after aspiration. In 27 patients, surgery was performed and all identified PCs were localized in the inferior parathyroid glands. Histologically, the cyst wall consisted in associations of lymphoid, muscular, thymic, salivary, adipose and mesenchymal tissues.

CONCLUSIONS

PCs are rare but should be included within the differential diagnosis of a neck lump. True PCs are non-functional. Pathological and immunohistochemical findings are suggestive of a branchial origin. Fine-needle aspiration may be curative and is diagnostic due to the characteristic appearance of the fluid and high PTH levels on assay.

ret/PTC1 and ret/PTC3 in thyroid tumors from Chernobyl liquidators: comparison with sporadic tumors from Ukrainian and French patients

Like children exposed to Chernobyl fallout, the workers who cleaned up after the accident, also known as liquidators, have exhibited an increased incidence of thyroid cancer. A high prevalence of ret/PTC3 rearrangement has been found in pediatric post-Chernobyl thyroid tumors, but this feature has not been investigated in liquidator thyroid tumors. In this study we analyzed the prevalence of ret/PTC1 and ret/PTC3 in thyroid tumors from 21 liquidators, 31 nonirradiated adult Ukrainian patients, and 34 nonirradiated adult French patients. ret rearrangements in carcinomas were found in 83.3% of liquidators, 64.7% of Ukrainian patients, and 42.9% of French patients. The prevalence of ret/PTC1 was statistically similar in the three groups. The prevalence of ret/PTC3 was significantly higher in liquidators than in French patients (P = 0.03) but it was also high in nonirradiated Ukrainian patients who exhibited values intermediate between liquidators and French patients. In adenomas the prevalence of rearrangement was significantly higher in all Ukrainians than in French patients (P = 0.004). Like children exposed to Chernobyl fallout, liquidators showed a high prevalence of ret/PTC3. This finding suggests that irradiation had the same effect regardless of age. However, given the high rate of ret/PTC3 in nonirradiated adult Ukrainians, the possibility of genetic susceptibility or low-level exposure to radiation in that group cannot be excluded.

Lymph node involvement in macroscopic medullary thyroid carcinoma

Background

Medullary thyroid carcinoma (MTC) is a rare disease, with variable tendency to lymphatic spread. The aim of this retrospective study was to identify distinctive features of large MTC with and without nodal metastases.

Methods

Between 1993 and 2003, 28 consecutive patients underwent total thyroidectomy and neck node dissection for sporadic MTC larger than 10 mm in diameter.

Results

All tumours were confirmed to be malignant with a locally invasive pattern of growth. Lymph node metastases were present in 16 patients (N1) and absent in 12 (N0). There were no statistically significant differences between patients with N0 and N1 tumours concerning age (mean 52·1 versus 53·4 years), male:female ratio (0·7 versus 1·0), basal preoperative calcitonin concentration (mean 3238 versus 3076 pg/ml) and tumour size (23·3 versus 23·9 mm). There were differences in the incidence of tumour invasion (P &lt; 0·001), vascular embolism (P = 0·011) and peritumoral thyroiditis (P = 0·039). Measurement of basal and stimulated calcitonin levels after surgery confirmed biochemical cure in all patients with N0 tumours and half of those with N1 disease (P = 0·006).

Conclusion

There were no preoperative factors that predicted node status for MTC larger than 1 cm in this series. Total thyroidectomy and nodal dissection remains the optimal treatment.

Endoscopic parathyroid surgery: results of 365 consecutive procedures

In recent years, several series have documented the feasibility of endoscopic approaches for parathyroid diseases. We performed a retrospective study to evaluate the results of endoscopic parathyroidectomy (EP) in the management of our patients with primary hyperparathyroidism (PHPT). During a 5.5 year period (1998-2003), we operated on 644 patients with PHPT. EP was proposed for patients with sporadic PHPT, without associated goiter, and without previous neck surgery in whom a single adenoma was localized by means of sonography and sestamibi scanning. EP was performed by the lateral approach with insufflation for patients with an adenoma located deep in the neck and by a gasless midline approach for patients whose adenoma was located anteriorly. A quick parathyroid (QPTH) assay was used during the surgical procedures. Among 644 patients with PHPT, 279 (43.3%) were not eligible for EP for the following reasons: associated nodular goiter (116 cases), previous neck surgery (52 cases), suspicion of multiglandular disease (31 cases), lack of preoperative localization (61 cases), and miscellaneous causes (19 cases). EP was performed in 365 patients with sporadic PHPT: 339 lateral access, 25 midline access, and one thoracoscopy. The median operating time was 49 minutes (16-130 minutes). Conversion to conventional parathyroidectomy was required in 49 patients (13.4%) for these reasons: missed adenomas (14 cases), difficulty with the dissection (8 cases), multiglandular disease correctly predicted by QPTH (11 cases), false-negative QPTH assay results (4 cases), false-positive sestamibi scan results (11 cases), and 1 false-positive sonography result. One patient presented with definitive recurrent nerve palsy. Three patients remained hypercalcemic, and one other patient had recurrent hypercalcemia. In conclusion, EP can be proposed for more than half of the patients with PHPT. Immediate results of EP are similar to those obtained with conventional parathyroidectomy, but no conclusions can be drawn in terms of the influence of EP on the outcome of the patients operated on for PHPT.

[Gastrinomas in multiple endocrine neoplasia type-1. A 127-case cohort study from the endocrine tumor group (ETG)]

On July 2000, 127 gastrinomas (31.1%) were studied by the Endocrine Tumour Group (GTE) using a 408-patient cohort of Multiple Endocrine Neoplasia Type 1 patients. The aim of this study was to assess clinical, biological, surgical data as well as their trends over three periods (<1980-1980/1989->1990). A Zollinger-Ellison syndrome (SZE) was present in 96% of the cases. Mean age at the onset of the disease was 39.4 years. There were 55.9% of men. Synchronous liver metastasis was present in 7.1%. Taken independently, the positivity of the four main diagnosis tests decreased over the time. The diagnosis of oesophagitis increased (4.5-29.7%), as well as the size of the resected tumours (9.9-16.8 mm). There was an increase in the familial background diagnosis (73.1-80%), an increasing use of Octreoscan scintigraphy and transduodenal ultrasound with positive detection of metastasis and tumours in 81.3% and 92.3%, respectively after 1991. Patients were operated on less frequently (96-52.5%), less frequently from the pancreas (87.5-37.5%), and from the gastro-intestinal tract (70.8-30%). The relative percentage of major pancreatic resections increased (with at least removal of the duodenum and the pancreatic head) (10-26.7%). The operative mortality disappeared. Six out of the seven patients (85.7%) who benefited from major pancreatic resections normalized their gastrine level postoperatively versus 15% in less radical techniques. Overall 5 years survival was 90 +/- 4.4%. Survival increased after 1985 (85 +/- 4.8% versus 95 +/- 3.6, P = 0.1).

CONCLUSION

SZE in NEM1 were diagnosed at an earlier stage and were less frequently operated on. Nevertheless, the incidence of synchronous metastasis did not change significantly. Patients were mainly operated on for gastric emergencies and pancreatic tumours in order to prevent metastasis without mortality after 1991.

Results of surgical treatment of sporadic medullary thyroid carcinoma following routine measurement of serum calcitonin

AIM

The aim of this study was to evaluate the results of the surgical management of medullary thyroid carcinoma (MTC), following the introduction of systematic calcitonin measurement in patients referred for thyroid diseases.

METHOD

We included all the patients with elevated calcitonin and MTC from January 1993 to March 2001.

RESULTS

Among 8497 patients, MTC was diagnosed in 52 with a mean age of 56.1 years. Thirty-two fine needle biopsies led to diagnose MTC in 19 cases. The median basal pre-operative calcitonin level was 245 pg/ml. Elevated calcitonin serum was the only indicator of MTC in 31 patients. Fifty-one patients underwent total thyroidectomies, with lymphadenectomy in 45. Thirteen patients had lymph node involvement. Post-operatively, 40 (77%) had normal basal and pentagastrin (Pg) stimulated calcitonin serum levels, and remained normal at a mean follow-up of 5.16 years (1.8-8).

CONCLUSION

Routine pre-operative measurement of calcitonin should be performed because it is often the only indicator of MTC at an early stage. This could lead to an improved MTC cure rate.

Does iodine-131 meta-iodobenzylguanidine (MIBG) scintigraphy have an impact on the management of sporadic and familial phaeochromocytoma?

OBJECTIVES

To assess the impact of [(131)I]meta-iodobenzylguanidine ((131)MIBG) scintigraphy on the management of phaeochromocytoma.

DESIGN AND PATIENTS

Between 1982 and 2002, 83 patients with histologically proven phaeochromocytoma or paraganglioma were investigated using (131)MIBG scintigraphy. Seventeen of these patients, with a hereditary form of the disease, presented with 23 phaeochromocytomas [three neurofibromatosis type 1 (NF1), five von Hippel-Lindau disease (VHL), eight multiple endocrine neoplasia type 2A (MEN2A) and one type 2B (MEN2B)].

RESULTS

MIBG uptake was observed in 44/54 sporadic phaeochromocytomas (sensitivity 81.5%), 14/23 familial phaeochromocytomas (60.9%), 3/6 paragangliomas and 4/6 malignant phaeochromocytomas. No significant correlations were found between the degree of tracer uptake, tumour size and urinary metanephrine levels. No patients undergoing surgery for sporadic phaeochromocytoma had a second tumour located. Nine of 54 sporadic phaeochromocytomas had normal or mildly elevated urinary metanephrine levels (< 1.5 greater than normal). In eight of these patients, (131)MIBG was positive and confirmed the diagnosis of phaeochromocytoma. In malignant phaeochromocytomas (n = 6), MIBG demonstrated additional lesions not detected with computed tomography (CT) and/or magnetic resonance imaging (MRI) in three cases. The MIBG findings in the group with apparently sporadic paragangliomas (n = 6) were negative in four cases and failed to detect a cervical lesion in one multifocal paraganglioma.

CONCLUSION

(131)MIBG was useful in confirming the diagnosis in phaeochromocytomas with low levels of catecholamine secretion. It contributed little to the management of patients when used as a means of screening for multifocality in sporadic phaeochromocytoma, or the management of patients with familial phaeochromocytoma. However, MIBG can be an informative method of investigation when dealing with malignant/ectopic forms, although the sensitivity of MIBG is lower in this group of patients.

[New surgical approaches to primary hyperparathyroidism]

We have seen recently the appearance of several new techniques for parathyroidectomy: the minimally invasive techniques all have a limited incision when compared to classic transverse cervical incision and are targeted on one specific parathyroid gland. These interventions are today possible for three main reasons: the available imaging techniques permit to locate the diseased gland, the use of rapid intraoperative PTH assay can confirm the successful extirpation, new instrumentation and miniaturised cameras have been adapted for this kind of surgery. Amongst minimally invasive techniques applied to parathyroidectomy, the video-assisted technique has the main advantage to offer a magnified view that permits a precise and careful dissection with minimal risks. Not all patients presenting a primary hyperparathyroidism are candidates for this surgery. Contraindications are mainly due to a large goiter, previous surgery in the parathyroid vicinity, suspicious multiglandular disease and equivocal preoperative localising studies. Currently 60% of patients with primary hyperparathyroidism can benefit of these techniques. Studies comparing conventional parathyroid surgery to endoscopic techniques have shown a diminution of postoperative pain and better cosmetic results with endoscopic techniques. If early results are similar to those obtained with conventional traditional open parathyroidectomies it is still too soon to evaluate what will be the recurrence rate of these new techniques.

Hématome cervical spontané secondaire à une hémorragie extracapsulaire d’un adénome parathyroïdien : à propos de 2 cas

The usual clinical manifestations of a parathyroid adenoma are due, in most of the cases, to hypercalcemia. The development of a spontaneous cervical or cervicomediastinal haematoma is a rare form of presentation. In case of a spontaneous cervical haematoma associated with dysphagia: measurement of serum calcium, phosphate and parathyroid hormone allows the diagnosis of haematoma due to extracapsular haemorrhage from a parathyroid adenoma. We report herein 2 cases.