1/42. Nonrecurrent laryngeal nerves: anatomic considerations during thyroid and parathyroid surgery.PURPOSE: In head and neck surgery, damage to the recurrent laryngeal nerve (RLN) during thyroid surgery is the most common iatrogenic cause of vocal cord paralysis. Identification of the RLNs and meticulous surgical technique can significantly decrease the incidence of this complication. Nonrecurrent RLNs (NRRLNs) are exceedingly rare. Surgeons need to be aware of their position to avoid damage to them. MATERIALS AND methods: A retrospective review of 513 RLN exposures over a 7-year period was performed. RESULTS: Two NRRLNs were encountered, for an incidence of 0.39%. CONCLUSION: NRRLNs are rare. awareness of their existence will prevent the surgeon from accidentally severing one if it is encountered during routine thyroid or parathyroid surgery.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
2/42. A premature stopcodon in thyroglobulin messenger rna results in familial goiter and moderate hypothyroidism.Impaired thyroglobulin (Tg) synthesis is one of the putative causes for dyshormonogenesis of the thyroid gland. This type of hypothyroidism is characterized by intact iodide trapping, normal organification of iodide, and usually low serum Tg levels in relation to high TSH, and when untreated the patients develop goiter. In thyroid tissue from a 13-yr-old patient suspected of a thyroglobulin synthesis defect, the Tg mRNA was studied. The complete coding region of 8307 bp was directly sequenced and revealed a homozygous point mutation: a C886T transition in exon 7. Upon translation this mutation would result in a stopcodon at amino acid position 277, replacing the arginine residue. A Tg cDNA construct containing the mutation was expressed in rabbit reticulocyte lysate resulting in a truncated protein of 30 kDa. Expression in the presence of microsomal membranes resulted in a gel shift of this Tg molecule, indicating glycosylation ability. Two other siblings had a clinical presentation like the index patient, while their parents were unaffected. Additional restriction fragment length polymorphism analysis of the pedigree verified that the homozygous nonsense mutation cosegregated with the clinical phenotype. Clinically, hypothyroidism was not severe in the affected siblings because the truncated Tg glycoprotein was still capable of thyroid hormonogenesis.- - - - - - - - - - ranking = 0.26426069748104keywords = organ (Clic here for more details about this article) |
3/42. Papillary carcinoma in amyloid goitre.Amyloid goitre is a rare lesion characterized by a diffuse and bilateral enlargement of the thyroid gland due to amyloid deposition. It is uncommon that a massive and widespread amount of adipose tissue deposition is found within these lesions and only in exceptional cases a differentiated carcinoma can develop. We describe the third example of thyroid carcinoma, arising in a 74-year old female who had also massive adipose thyroidal metaplasia, within amyloid goitre. The congo red stain confirmed the diagnosis of amyloid goitre. immunohistochemistry showed reactivity with MoAb against amyloid fibril protein A. The patient suffered from renal failure of undetermined aetiology for three years, but neither systemic amyloidosis nor risk factors for its development were found. It is important to correctly diagnose amyloid goitre both to rule out the presence of a differentiated thyroidal carcinoma and to search for amyloid infiltration in other organs in view of an early appropriate therapy.- - - - - - - - - - ranking = 0.26426069748104keywords = organ (Clic here for more details about this article) |
4/42. Amyloid goiter as the initial manifestation of systemic amyloidosis due to familial mediterranean fever with homozygous MEFV mutation.We describe a case of amyloid goiter revealing a systemic amyloidosis secondary to familial mediterranean fever (FMF) with homozygous MEFV mutation, and we review the literature. A 45-year-old euthyroid Sephardic man, known to suffer from FMF, developed a goiter with cold nodule, after which a subtotal thyroidectomy was performed. Histologic evaluation revealed diffuse AA amyloid deposition without any associated thyroid neoplasia. At that time, no other organ was found to be affected by amyloidosis. colchicine and levothyroxine were prescribed. Eight years later, the patient presented with a rapidly growing neck enlargement. He reported that he had discontinued colchicine therapy 2 years earlier. The serum thyrotropin (TSH) and calcitonin levels were normal. Renal, digestive, and salivary gland biopsies confirmed the presence of systemic AA amyloidosis. Despite the reintroduction of colchicine, the onset of compressive symptoms led to the completion of the total thyroidectomy. The histopathology again demonstrated amyloid deposition, and excluded a malignant neoplasm. Nine cases of amyloid goiter associated with FMF have been reported in the literature; none of them had an amyloid goiter as the first manifestation of systemic amyloidosis. To our knowledge, this is the first case of FMF in which an amyloid goiter preceded the development of secondary systemic amyloidosis. The cessation of colchicine therapy may have played a role in local relapse and the secondary spread of amyloid deposits.- - - - - - - - - - ranking = 0.26426069748104keywords = organ (Clic here for more details about this article) |
5/42. Clinical and molecular analysis of three Mexican families with Pendred's syndrome.BACKGROUND: The autosomal recessive Pendred's syndrome is defined by congenital sensorineural deafness, goiter, and impaired iodide organification. It is caused by mutations in the Pendred's syndrome (PDS) gene that encodes pendrin, a chloride/iodide transporter expressed in the thyroid, the inner ear, and the kidney. OBJECTIVE: To perform a detailed clinical and molecular analysis of patients with Pendred's syndrome from four patients from three unrelated Mexican families. methods: thyroid function tests, perchlorate test, thyroid scintigraphy, audiometry, computer tomography and magnetic resonance imaging were performed in all affected individuals. Haplotype analyses were performed using microsatellite markers flanking the PDS locus, and the PDS gene was submitted to direct sequence analysis. RESULTS: All patients presented with sensorineural deafness, Mondini malformations of the cochlea, an enlarged vestibular aqueduct, goiter, and a positive perchlorate test. Two patients were hypothyroid, two individuals were euthyroid. sequence analysis revealed a complex homozygous deletion/insertion mutation at the end of exon 4 in the index patient of family 1 resulting in a premature stop codon at position 138. In family 2, the affected individuals were compound heterozygous for a splice acceptor mutation (IVS2 -1G>A) and a 1231G>C transversion substituting alanine 411 by proline (A411P). In family 3, the index patient was found to be homozygous for a transversion 412G>T in exon 4 replacing valine 138 by phenylalanine (V138F). CONCLUSIONS: All patients included in this study presented with the classic Pendred syndrome triad and molecular analysis revealed pendrin mutations as the underlying cause. The identification of three novel mutations, one of them of complex structure, expands the spectrum of mutations in the PDS gene and emphasizes that they display marked allelic heterogeneity.- - - - - - - - - - ranking = 0.26426069748104keywords = organ (Clic here for more details about this article) |
6/42. Langerhans cell histiocytosis of the thyroid: a report of two cases and review of the literature.Langerhans cell histiocytosis (LCH) is a monoclonal disease of histiocytes that can involve many or very few organ systems. It is a relatively benign disorder with a 3% mortality in adults. LCH rarely involves the thyroid gland. We report two cases, both presenting in males with a goiter. Both patients were treated with subtotal thyroidectomy. The first patient also received radiotherapy to his thyroid bed and scalp. We summarize the prior reported cases of LCH involving the thyroid and review the current treatment modalities used for LCH.- - - - - - - - - - ranking = 0.26426069748104keywords = organ (Clic here for more details about this article) |
7/42. Deficient cytochrome b5 reductase activity in nontoxic goiter with iodide organification defect.A 37-yr-old woman with nontoxic goiter is presented. The thyroid 131I uptake at 3 and 24 hr were, respectively, 77.1% and 81.4% dose. Thiocyanate discharged 65.5% of the accumulated 131I in 30 min. in vitro organification of iodine in the thyroid homogenate from the patient was impaired and it was restored to normal by the addition of H2O2, glucose, and glucose oxidase system, FAD, or reduced cytochrome b5. riboflavin, FMN, oxidized cytochrome b5, oxidized or reduced cytochrome c, NAD(H), and nadp(H) were ineffective in the reaction. The microsomal NADH-cytochrome b5 reductase activity was definitely low in the patient's thyroid. It was augmented to a normal level by incubation of the microsomes with FAD for 30 min or more. The activities of thyroid peroxidase, G6-PD, 6-PGD, catalase, protease, and NADPH-cytochrome c reductase were within normal limits. The major thyroid protein was normal thyroglobulin which could be readily iodinated in the presence of H2O2 and horse radish peroxidase. These findings suggest the correlation of an iodide organification defect with a cytochrome b5 reductase deficiency. Administration of high doses of FAD led to the restoration of thyroidal iodide organification mechanism associated with an increased thyroid hormone production and to a marked decrease of the goiter. riboflavin was given without effect even at a high dosage level. Consequently, it seems likely that the deficient cytochrome b5 reductase activity in this patient is due to a defect in the biosynthesis of FAD, the coenzyme of the reductase, from riboflavin.- - - - - - - - - - ranking = 1.8498248823673keywords = organ (Clic here for more details about this article) |
8/42. Amyloid goiter in familial mediterranean fever (FMF): a clinicopathologic study of 10 cases.FMF amyloidosis is an important etiological factor of end stage renal disease (ESRD) in Mediterranean Countries. Apart from major target organs as cardiovascular, respiratory and gastrointestinal system, endocrine organs can also be involved. We planned to investigate the thyroid involvement in our amyloidosis group. The aim of this study was to determine clinical characteristics of amyloid goiter in FMF patients and the abnormalities of thyroid function, as well as to identify pathologic characteristics. Twenty-two hemodialysis patients (mean age 34.1 /- 14 years, range 17-68) whose ESRD secondary to FMF amyloidosis were evaluated with physical examination, serum levels of thyroid hormones, ultrasound examination of thyroid glands, thyroid syntigraphic studies. goiter was found in 10 patients (4 male, 6 female) having enlarged neck mass (mean age 35 /- 14 years, range 23-64). The serum levels of thyroid hormones and TSH were normal in 4 patients. Other four cases had euthyroid sick syndrome. Only one patient developed tender enlarged neck mass with subacute thyroiditis symptoms and one had primary hyperthyroidism. Ultrasound examination showed; hypoecoic nodules in 6 patients diffuse multinodular enlargement in 4 patients. Thyroid syntigraphic studies revealed hypoactive nodules in 7 patients and hyperactive nodules in 3 patients. After the laboratory tests were completed, in 10 patients diagnosis were made with fine needle aspiration biopsy. Of 10 patients 5 underwent subtotal thyroidectomy. Immunohistochemical evaluation demonstrated the presence of amyloid AA immunoreactivity in all cases. In conclusion fine needle aspiration from the thyroid when enlarged is useful in the diagnosis of suspected amyloidosis, especially since it is a safe, easily performed procedure. With the help of amyloid goiter diagnosis the patient's prognosis on hemodialysis and with renal transplantation can be predicted. Amyloid goiter must be searched in hemodialysis patients especially in Mediterranean Countries.- - - - - - - - - - ranking = 0.52852139496209keywords = organ (Clic here for more details about this article) |
9/42. Amyloid goiter--a case report.Microscopic infiltration of the thyroid gland by amyloid is an uncommon but well recognized phenomenon and significant enlargement of the thyroid due to deposition of amyloid is rarely seen. This condition has to be distinguished from other types of goiters and at times from malignancy. In spite of extensive involvement of the gland by amyloid, thyroid function usually remains normal. Here, we describe a rare case of amyloid goiter without amyloid deposits in any other organs of the body. The case presented in an unusual clinical settings of relatively rapid enlargement of thyroid with pressure symptoms and was unassociated with any immuno-proliferative or chronic diseases.- - - - - - - - - - ranking = 0.26426069748104keywords = organ (Clic here for more details about this article) |
10/42. Two novel missense mutations in the thyroid peroxidase gene, R665W and G771R, result in a localization defect and cause congenital hypothyroidism.OBJECTIVE: Thyroid peroxidase (TPO) deficiency is one of the causes of thyroid dyshormonogenesis, because TPO plays a key role in thyroid hormone biosynthesis. To determine the frequency and pattern of TPO abnormalities, we have been screening TPO genes of patients with congenital goitrous hypothyroidism. SUBJECTS AND methods: TPO genes of a patient with congenital goitrous hypothyroidism and her parents were directly sequenced, and two novel missense mutations (R665W and G771R) were found. The former was derived from her father and the latter from her mother. R665 and G771 were well conserved in the peroxidase superfamily. When mRNAs containing each of the mutations were transfected into CHO-K1 cells, each cell showed faint TPO enzyme activity. However, immunofluorescence and immunoelectron microscopic analyses revealed that neither of the mutated TPOs reached the plasma membrane. CONCLUSIONS: Two novel missense mutations in the TPO gene were found. TPO proteins encoded by these mutated alleles showed abnormal cellular localization; namely, localization on the plasma membrane was disturbed. The loss of plasma membrane localization in mutated TPOs brought about the iodide organification defect, which was diagnosed as congenital hypothyroidism.- - - - - - - - - - ranking = 0.26426069748104keywords = organ (Clic here for more details about this article) |
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