11C-Methionine PET/CT in patients with primary hyperparathyroidism and inconclusive pre-operative imaging work-up: diagnostic accuracy and role of semi-quantitative analysis.

OBJECTIVE: 11C-Methionine PET/CT (C-MET) is a promising method in detecting abnormal parathyroid glands in patients with primary hyperparathyroidism (PHPT). The first aim of the study was to evaluate which is the diagnostic role of C-MET in patients with PHPT and inconclusive pre-operative imaging. Second, we aimed to investigate whether C-MET semi-quantitative parameters may reflect biochemical and histological characteristics of involved glands. METHODS: Patients with PHPT, undergoing C-MET after an inconclusive pre-operative imaging and having a parathyroid surgery, were retrospectively included. C-MET visual and semi-quantitative assessment was performed. Parameters, as SUVmax, SUVpeak, SUVmean, functional lesion volume (FLV) and total lesion activity (TLA), were measured for each detected lesion; SUVmean, FLV and TLA were calculated on 40-90% thresholds of SUVmax to define SUVmean40-90, FLV40-90 and TLA40-90, respectively. Results were correlated with patients' clinical-laboratory (calcium and PTH values) and histological data (size and weight of excised glands). Mann-Whitney test was used and P value < 0.05 was considered significant. RESULTS: Thirty-eight patients (36 female, age: 57.69 ± 15.13 years) were included. Pre-operative median calcium and PTH values were 11.1 mg/dl [interquartile range (IQR) 10.6-11.5] and 154.6 pg/ml (IQR 101.8-227.0), respectively. C-MET showed a parathyroid uptake in 30 out of thirty-eight patients (78.9%). Among 42 nodules excised, C-MET correctly detected the side of the neck (right/left) in 30/42 with sensitivity, specificity and accuracy of 79, 75 and 79%, respectively. C-MET correctly identified the exact position (superior/inferior) in 27/42 with sensitivity, specificity and accuracy of 75, 50 and 71%, respectively. SUVpeak, FLV50-70 and TLA40-70 were significantly (P < 0.05) higher in patients with higher PTH results. The histological size resulted significantly (P < 0.05) higher in abnormal glands with higher SUVmax, SUVpeak, FLV40-80 and TLA40-90, the weight was higher in glands with higher SUVpeak, SUVmean40-50, FLV40-80 and TLA40-90. CONCLUSIONS: C-MET showed a good performance in detecting hyperfunctioning parathyroid glands in PHPT patients with inconclusive pre-operative imaging. Semi-quantitative PET-derived parameters closely correlated with PTH as well as with size and weight of the excised gland, thus reflecting some biochemical and histological characteristics of involved glands.

Persistent secondary hyperparathyroidism caused by parathyromatosis and supernumerary parathyroid glands in a patient on haemodialysis.

BACKGROUND: Secondary hyperparathyroidism (SHPT) is a common high-risk factor for mortality in end-stage renal disease, and parathyromatosis and supernumerary parathyroid glands are very rare causes of persistent SHPT. Preoperative diagnosis and removal of all hyperplastic parathyroid glands are challenging. We report a rare case of persistent SHPT due to parathyromatosis and supernumerary parathyroid glands and successful management by multiple imaging modalities. CASE PRESENTATION: A 53-year-old Chinese woman on haemodialysis experienced discomfort due to itching and bone pain due to persistent SHPT after parathyroidectomy. The supernumerary parathyroid glands and parathyromatosis were detected by multiple imaging modalities, including 99mTc-sestamibi (99mTc-MIBI) scans, ultrasonography and four-dimensional computed tomography (4D-CT) and then excised; pathological confirmation was performed. During follow-up, her serum calcium and parathyroid hormone levels were stable in the appropriate ranges, and no complications arose. CONCLUSIONS: Because of persistent SHPH after parathyroidectomy in patients with haemodialysis, multiple imaging modalities, including 99mTc-MIBI scans, 4D-CT and ultrasonography, are helpful for detecting supernumerary parathyroid glands and parathyromatoses. Accurate preoperative localization of this rare lesion is important for management, enabling the removal of all affected parathyroid tissues.

Refractory hypercalcemia due to an ectopic mediastinal parathyroid gland in a hemodialysis patient: a case report.

BACKGROUND: Hypercalcemia crisis is a complex disorder rarely induced by tertiary hyperparathyroidism, which clinically presents as nonsuppressible parathyroid hyperplasia with persistent increased PTH levels and hypercalcemia. It is one of the major risk factors of morbidity and mortality in end-stage renal disease. Parathyroidectomy should be in consideration in dialysis patients with severe hyperparathyroidism who are refractory to medical therapy. The implications and consequences of it, however, are not fully understood. CASE PRESENTATION: We present a case of a 70 year-old man disturbed by gastrointestinal manifestations due to hypercalcaemic crisis. The patient had longstanding hypercalcaemia and hyperparathyrodism refractory to calcimimetics, calcitonin, hormone and haemodialysis. A ectopic parathyroid gland in anterior mediastinum was found and elucidated by Tc-99 m scan. Futhermore, a video-assisted thoracoscopic parathyroidectomy was performed. Histologically, the tumour consisted of densely arranged chief cells immunohistochemically positive for PTH antigens. Consequently, calcium and parathormone were declining stably without any complications. CONCLUSIONS: On account of refractory hypercalcemia and hyperparathyroidism, radionuclide scanning is useful in the diagnosis of ectopic parathyroid gland. it is of great significance for multidisciplinary therapy combing anesthesia, surgical, endocrinology and nephrology staff.

Thyroid hemiagenesis and Hashimoto's thyroditis-diagnostic and treatment pitfalls.

BACKGROUND: Thyroid hemiagenesis (TH) is a rare congenital disease with absence of a thyroid lobe; most patients have no clinical symptoms. The etiology of TH remains unclear. In this paper, we describe a rare case of TH and congenital absence of the ipsilateral parathyroid gland, found during the operation, combined with the autoimmune disease Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis. CASE PRESENTATION: A 31-year-old woman was admitted to our hospital because of a mass in the right neck. Surgical exploration validated the absence of the left lobe of the thyroid and parathyroid glands, and pathological examination of the excised nodules confirmed Hashimoto's thyroiditis. Patients with TH might show accompanying absence of the ipsilateral parathyroid gland. The case described here, in which TH was combined with Hashimoto's thyroiditis, is rare in the medical literature. The operation should be ended at once if Hashimoto's thyroiditis is diagnosed during surgery. CONCLUSIONS: Absence of thyroid lobe may accompany with a congenital absence of the ipsilateral parathyroid gland and Hashimoto's thyroiditis. Fine needle aspiration is essential to diagnosis and decision-making of the treatment.

[Videothoracoscopic excision of mediastinal parathyroid adenoma in primary hyperparathyroidism]. / Videothorakoskopické odstranení mediastinálne ulozeného adenomu prístítného telíska pri primární hyperparathyreóze.

INTRODUCTION: Primary hyperparathyroidism is a disease caused by elevated secretion of parathyroid hormone from pathological parathyroid glands. After the diagnosis, the success of its surgical solution depends predominantly on surgical management and experience of the surgeons. A special group is formed by ectopic localizations of pathologically enlarged parathyroid glands in the mediastinum, which require a modified surgical approach. When the adenoma is deep in the mediastinum, sternotomy or thoracotomy is indicated; alternatively, a minimally invasive approach can be used - videothoracoscopic thymectomy. CASE REPORT: We present a case of a patient with normocalcemic recurrent primary hyperparathyroidism. This patient underwent a minimally invasive video-assisted thymectomy after scintigraphic confirmation of parathyroid adenoma in the mediastinum. CONCLUSION: The removal of parathyroid adenoma in the mediastinum using the videothoracoscopic method is safe. Compared to sternotomy, this method improves the postoperative period, reduces the length of stay and provides more comfort to patients. We recommend considering the videothoracoscopic method in cases where the pathologically enlarged parathyroid gland is localized in the inferior and anterior mediastinum. KEY WORDS: primary hyperparathyroidism adenoma of glandula parathyroidea - mediastinum miniinvasive.

Technical Factors Involved in Parathyroid Surgery.

We aimed to investigate the frequency of ectopic and supernumerary parathyroid glands in our series of renal hyperparathyroidism. From October 2011 to November 2014, 202 patients with chronic renal failure and advanced SHPT nonresponsive to medical therapy were hospitalized in the General Surgery Department of the Carol Davila Nephrology Hospital. These patients underwent a number of 188 (93%) total parathyroidectomies and a number of 14 patients (7%) subtotal parathyroidectomies. Of these 202 patients, reoperation was carried out for 14 patients (7%) in which we identified ectopic and supernumerary parathyroid glands. Operative details and pathology results were prospectively collected and reviewed after we obtained informed consent for data and pictures use. In 188 patients (93% cases), four or more parathyroid glands were removed at the first operation. In 14 cases (7%) high PTH level persisted after the initial operation. In 22 of them (11%), supernumerary glands were found at the first operation and in 6 of them (3%) at the second operation. We conclude that extensive cervical exploration in addition with preoperative imaging tests, parathyroid ultrasound; scintigraphy with Tc will reduce secondary hyperparathyroidism surgery.

Adenomas of cervical maldescended parathyroid glands: pearls and pitfalls.

BACKGROUND: Missed parathyroid adenoma (PTA) is the commonest cause of persistent hyperparathyroidism. Although many are subsequently found in well-described locations, some are found in unusual regions of the neck. This paper presents the combined experience of three large tertiary endocrine surgery centres with maldescended PTA (MD-PTA). METHODS: Patients were recruited from the endocrine surgical databases of three tertiary endocrine surgery units. Patients with PTA found >1 cm above the superior thyroid pole or other cervical locations as a result of abnormal or incomplete descent were included for analysis. RESULTS: MD-PTA was identified in 16 patients out of a total of 5241 patients who had undergone parathyroidectomies in the 7-year study period (incidence 0.3%). Seven (44%) patients had minimally invasive parathyroidectomy, while nine (56%) had bilateral neck exploration. The mean excised gland weight was 750 + 170 mg. Cure was achieved in all patients with a minimum follow-up of 6 months. The locations of MD-PTA in this study included submandibular triangle, retropharyngeal space, carotid sheath (at carotid bifurcation and intravagal), parapharyngeal space (superior to thyroid cartilage or superior thyroid pole) and cricothyroid space. CONCLUSIONS: Despite their rare occurrence, incompletely or abnormally descended PTAs can be encountered by any surgeon who performs parathyroidectomies. It is important to develop a strategy to systematically locate these glands. High cure rates can still be achieved with minimally invasive parathyroidectomy if confident preoperative localization is available. A sound knowledge of embryology and a thorough exploration also facilitate an overall high success rate with open exploration.

Dissection and identification of parathyroid glands during thyroidectomy: association with hypocalcemia.

BACKGROUND: The purpose of this study was to evaluate preoperative features, surgical details, and postoperative findings related to the identification of parathyroid glands and to establish the relationship between identification of parathyroid glands and postoperative hypocalcemia. METHODS: Seven hundred eighty-eight total thyroidectomies performed between January 2002 and April 2012 by a single surgeon were studied. To evaluate the impact of parathyroid glands identification on study variables, patients were stratified into 2 study groups: group 1 with 0 to 2 parathyroid glands identified and group 2 with 3 to 4 parathyroid glands identified. RESULTS: Multivariate analysis identified younger age (p = .007), female sex (p = .001), and no usage of the Biclamp hemostatic technique (p < .001) related to the higher number of parathyroid glands identified. Univariate analysis revealed a higher incidence of temporary hypocalcemia (p = .015) and permanent hypoparathyroidism (p = .040) in group 2 than in group 1. CONCLUSION: Identification of a higher number of parathyroid glands is associated with a higher incidence of postoperative temporary hypocalcemia and permanent hypoparathyroidism.

Adult perithyroid and cervical thymus-parathyroid unit: case reports of a rare entity.

The thymus-parathyroid unit (TPU) occurring in adults is rare.The main symptoms and important clinical findings are as follows: 2 patients presented with neomercazole-resistant Basedow-Graves disease. A third patient presented with thyroid nodules and a fourth patient with a neck mass after thyroid resection for medullary thyroid carcinoma.The main diagnoses were those of thyroid nodules (either in the context of goiter, or not). In the fourth case the diagnosis was of thyroid medullary carcinoma recurrence in the neck. Thyroidectomy was performed in the 2 cases of Basedow-Graves disease and in the third case (wherein selective neck dissection was also performed). In the fourth case, a neck dissection was performed for a possible medullary carcinoma recurrence. A TPU was microscopically detected in 2 cases with perithyroid location, on thyroidectomies for Basedow-Graves disease and in the 2 other cases with neck soft tissue location (associated with thyroid papillary carcinoma and thyroid medullary carcinoma extension). Postsurgical hypocalcemia requiring treatment occurred in both patients with Basedow-Graves disease and in the fourth patient. The presence of TPU should be acknowledged because such lesions can be misdiagnosed as suspect lymph nodes during thyroid surgery for malignant tumors.

[Ectopic parathyroid glands. Imaging methods and surgical access]. / Ektopická parathyreoidea, zobrazovací metody a chirurgické prístupy.

We discuss the benefits of imaging methods in localizing ectopic parathyroid glands in patients with primary hyperparathyroidism. The ectopic localizations are discussed within the context of the orthotopic norm. In the sample of 123 patients, a 23% rate of ectopic parathyroid glands was detected. Three selected case studies are presented, supporting the benefit of SPECT/CT imaging in terms of surgical access strategy selection.

Localization of ectopic and supernumerary parathyroid glands in patients with secondary and tertiary hyperparathyroidism: surgical description and correlation with preoperative ultrasonography and Tc99m-Sestamibi scintigraphy.

INTRODUCTION: Hyperparathyroidism is an expected metabolic consequence of chronic kidney disease (CKD). Ectopic and/or supernumerary parathyroid glands (PT) may be the cause of surgical failure in patients undergoing total parathyroidectomy (PTX). AIM: To define the locations of ectopic and supernumerary PT in patients with renal hyperparathyroidism and to correlate intraoperative findings with preoperative tests. MATERIALS AND METHODS: A retrospective study was conducted with 166 patients submitted to PTX. The location of PT during surgery was recorded and classified as eutopic or ectopic. The preoperative localizations of PT found by ultrasonography (USG) and Tc99m-Sestamibi scintigraphy (MIBI) were subsequently compared with intraoperative findings. RESULTS: In the 166 patients studied, 664 PT were found. Five-hundred-seventy-seven (86.4%) glands were classified as eutopic and 91(13.6%) as ectopic. Eight supernumerary PT were found. The most common sites of ectopic PT were in the retroesophageal and thymic regions. Taken together, USG and MIBI did not identify 56 (61.5%) ectopic glands. MIBI was positive for 69,7% of all ectopic glands located in the mediastinal and thymic regions. CONCLUSION: The presence of ectopic and supernumerary PT in patients with renal hyperparathyroidism is significant. Although preoperative imaging tests did not locate most of ectopic glands, MIBI may be important for identifying ectopic PT in the mediastinal and thymic regions.

Localizacao de glandulas paratireoides ectopicas e supranumerarias em pacientes com hiperparatireoidismo secundario e terciario: descricao cirurgica e correlacao com ultrassonografia e cintilografia Tc99m-Sestamibi pre-operatorios / Localization of ectopic and supernumerary parathyroid glands in patients with secondary and tertiary hyperparathyroidism: surgical description and correlation with preoperative ultrasonography and Tc99m-Sestamibi scintigraphy

Introdução: O hiperparatireoidismo é uma consequência metabólica esperada na doença renal crônica (DRC). Paratireoides (PT) ectópicas e/ou supranumerárias podem ser causa de falha cirúrgica nos pacientes submetidos à paratireoidectomia total (PTX). Objetivo: Definir cirurgicamente a localização das PT, em pacientes com hiperparatireoidismo associado à DRC, e correlacionar esses achados com os exames pré-operatórios. Materiais e métodos: Foi conduzido um estudo retrospectivo com 166 pacientes submetidos à PTX. A localização das PT no intraoperatório foi registrada, sendo classificada como tópica ou ectópica. A localização pré-operatória, definida pela ultrassonografia (USG) e pela cintilografia Tc99m-Sestamibi (MIBI), foi comparada com aos achados cirúrgicos. Resultados: Nos 166 pacientes, foram identificadas 664 PT. Foram classificadas como tópicas e ectópicas 577 (86,4%) e 91(13,6%) glândulas, respectivamente. Oito PT supranumerárias foram encontradas (7 tópicas e 1 ectópica). As localizações mais comuns de PT ectópicas foram as regiões retroesofágica e tímica. Associadas, a USG e a MIBI não identificaram 56 glândulas (61,5%) ectópicas. Entretanto, a MIBI foi positiva para 69,7% daquelas localizadas nas regiões tímicas e mediastinal. Conclusão: A presença de glândulas ectópicas e supranumerárias em pacientes com hiperparatireoidismo associado à DRC é significativa. Os exames de imagem pré-operatórios não localizaram a maioria das glândulas ectópicas. A MIBI pode ter importância na identificação de PT nas regiões tímica e mediastinal. .

Introduction: Hyperparathyroidism is an expected metabolic consequence of chronic kidney disease (CKD). Ectopic and/or supernumerary parathyroid glands (PT) may be the cause of surgical failure in patients undergoing total parathyroidectomy (PTX). Aim: To define the locations of ectopic and supernumerary PT in patients with renal hyperparathyroidism and to correlate intraoperative findings with preoperative tests. Materials and methods: A retrospective study was conducted with 166 patients submitted to PTX. The location of PT during surgery was recorded and classified as eutopic or ectopic. The preoperative localizations of PT found by ultrasonography (USG) and Tc99m-Sestamibi scintigraphy (MIBI) were subsequently compared with intraoperative findings. Results: In the 166 patients studied, 664 PT were found. Five-hundred-seventy-seven (86.4%) glands were classified as eutopic and 91(13.6%) as ectopic. Eight supernumerary PT were found. The most common sites of ectopic PT were in the retroesophageal and thymic regions. Taken together, USG and MIBI did not identify 56 (61.5%) ectopic glands. MIBI was positive for 69,7% of all ectopic glands located in the mediastinal and thymic regions. Conclusion: The presence of ectopic and supernumerary PT in patients with renal hyperparathyroidism is significant. Although preoperative imaging tests did not locate most of ectopic glands, MIBI may be important for identifying ectopic PT in the mediastinal and thymic regions. .

Imaging diagnostics for primary hyperparathyroidism.

Primary hyperparathyroidism (PHP) is a benign condition characterised by malignant potential. Even in specialist wards, 5-10% of operations for PHP are unsuccessful. The main reasons seem to be ectopy of the parathyroid gland, numerous adenomas, multiglandular parathyroid hyperplasia, and intrathyroid location of the parathyroid. The last three decades have witnessed a rapid progression in imaging diagnostics.

Patología hiperparatiroidea atendida en tres hospitales costarricenses / Hyperparathyroid pathology treated in three Costa Rican hospitals

Objetivo: determinar la frecuencia y características de los pacientes que por patología hiperparatiroidea, se atendieron en los hospitales México, San Juan de Dios y "Dr. Rafael Angel Calderón Guardia", en un periodo de tres años. Métodos: análisis de registros de parathormona intacta sérica elevada, expedientes clínicos y revisión bibliográfica. Estudio descriptivo, cuya muestra fue pacientes hiperparatiroideos atendidos entre enero 2007 y diciembre 2009. La determinación de frecuencias y proporciones para las variables cualitativas se realizó por medio de la prueba chi cuadrado, y las cuantitativas, mediante la estimación de la prueba t de student. Resultados: de 199 pacientes estudiados, se excluyeron 9. El sexo femenino predominó (68.9 por ciento), el grupo etario más frecuente fue de 60 y más años de edad (33,1 por ciento). El hiperparatiroidismo primario fue la enfermedad más frecuente (n=46;24,2 por ciento;73,9 por ciento mujeres, 69,5 por ciento mayores de 50 años), luego hipovitaminosis D y falla renal crónica. La mayoría vivía en San José (59,4 por ciento) y se atendió en el Hospital México (65,8 por ciento). No se posee el concepto claro y se desdeña el hiperparatiroidismo normocalcémico, por parte de algunos médicos, y la mayoría no solicita determinaciones de vitamina D. Discusión: los pacientes con parathormona intacta elevada por diversas causas están expuestos a muchas patologías que pueden comprometer su sobrevivencia y calidad de vida. La hipovitaminosis D probablemente sería más frecuente, si su medición se solicitara más. Debe enfatizarse la solicitud de calcecifediol en cualquier patología paratiroidea...

Supernumerary parathyroid glands in hyperparathyroidism associated with multiple endocrine neoplasia type 1.

OBJECTIVE: To evaluate frequency, anatomic presentation, and quantities of supernumerary parathyroids glands in patients with primary hyperparathyroidism (HPT1) associated with multiple endocrine neoplasia type 1 (MEN1), as well as the importance of thymectomy, and the benefits of localizing examinations for those glands. METHODS: Forty-one patients with hyperparathyroidism associated with MEN1 who underwent parathyroidectomy between 1997 and 2007 were retrospectively studied. The location and number of supernumerary parathyroids were reviewed, as well as whether cervical ultrasound and parathyroid SESTAMIBI scan (MIBI) were useful diagnostic tools. RESULTS: In five patients (12.2%) a supernumerary gland was identified. In three of these cases (40%), the glands were near the thyroid gland and were found during the procedure. None of the imaging examinations were able to detect supernumerary parathyroids. In one case, only the pathologic examination could find a microscopic fifth gland in the thymus. In the last case, the supernumerary gland was resected through a sternotomy after a recurrence of hyperparathyroidism, ten years after the initial four-gland parathyroidectomy without thymectomy. MIBI was capable of detecting this gland, but only in the recurrent setting. Cervical ultrasound did not detect any supernumerary glands. CONCLUSION: The frequency of supernumerary parathyroid gland in the HPT1/MEN1 patients studied (12.2%) was significant. Surgeons should be aware of the need to search for supernumerary glands during neck exploration, besides the thymus. Imaging examinations were not useful in the pre-surgical location of these glands, and one case presented a recurrence of hyperparathyroidism.

Supernumerary parathyroid glands in hyperparathyroidism associated with multiple endocrine neoplasia type 1 / Paratireoides supranumerárias em hiperparatireoidismo primário associado a neoplasia endócrina múltipla tipo 1

OBJECTIVE: To evaluate frequency, anatomic presentation, and quantities of supernumerary parathyroids glands in patients with primary hyperparathyroidism (HPT1) associated with multiple endocrine neoplasia type 1 (MEN1), as well as the importance of thymectomy, and the benefits of localizing examinations for those glands. METHODS: Forty-one patients with hyperparathyroidism associated with MEN1 who underwent parathyroidectomy between 1997 and 2007 were retrospectively studied. The location and number of supernumerary parathyroids were reviewed, as well as whether cervical ultrasound and parathyroid SESTAMIBI scan (MIBI) were useful diagnostic tools. RESULTS: In five patients (12.2%) a supernumerary gland was identified. In three of these cases (40%), the glands were near the thyroid gland and were found during the procedure. None of the imaging examinations were able to detect supernumerary parathyroids. In one case, only the pathologic examination could find a microscopic fifth gland in the thymus. In the last case, the supernumerary gland was resected through a sternotomy after a recurrence of hyperparathyroidism, ten years after the initial four-gland parathyroidectomy without thymectomy. MIBI was capable of detecting this gland, but only in the recurrent setting. Cervical ultrasound did not detect any supernumerary glands. CONCLUSION: The frequency of supernumerary parathyroid gland in the HPT1/MEN1 patients studied (12.2%) was significant. Surgeons should be aware of the need to search for supernumerary glands during neck exploration, besides the thymus. Imaging examinations were not useful in the pre-surgical location of these glands, and one case presented a recurrence of hyperparathyroidism.

OBJETIVO: Avaliação da frequência, da localização anatômica e do número de paratireoides extranumerárias em pacientes com hiperparatireoidismo primário (HPT1) associado a neoplasia endócrina múltipla tipo 1(NEM1), além da avaliação da importância da timectomia e da utilidade dos exames radiológicos para localização destes. MÉTODOS: Foram avaliados de forma retrospectiva 41 pacientes portadores de NEM1 com HPT1 submetidos a paratireoidectomia entre 1997 e 2007. O número de glândulas supranumerárias encontradas e a sua localização foram revisados, assim como a utilidade do ultrassom cervical e do SESTAMIBI (MIBI) de paratireoide como ferramentas diagnósticas. RESULTADOS: Em cinco pacientes (12,2%) foram identificadas glândulas supranumerárias. Em três destes (40%), as glândulas estavam próximas à glândula tireoide e foram encontradas durante a exploração cirúrgica. Os exames de imagem não foram úteis para a localização destas glândulas. Em um caso, apenas o exame anatomopatológico foi capaz de encontrar uma glândula extranumerária microscópica localizada no timo. No último caso, uma quinta glândula foi ressecada por meio de esternotomia após a recidiva do hiperparatireoidismo, cerca de 10 anos após a paratireoidectomia realizada sem timectomia na ocasião. Neste caso o MIBI detectou esta paratireoide apenas após a recidiva da doença. Em nenhum dos casos o ultrassom cervical foi capaz de detectar glândulas extranumerárias. CONCLUSÃO: A frequência de paratireoides supranumerárias em nossa casuística foi significativa (12,2%). Durante a exploração cervical, o cirurgião deve estar atento para localizar glândulas extranumerárias além do timo. Exames de imagem não foram úteis na localização préoperatória dessas glândulas, e em um caso houve recidiva do hiperparatireoidismo.

Unusually rapid growth of brown tumour in the mandible after parathyroidectomy associated with the presence of a supernumerary parathyroid gland.

The aim of this study is to report the case of a quick growing brown tumour in the jaw after a parathyroidectomy due to the presence of a rare fifth parathyroid gland. The patient had chronic renal disease and the diagnosis was tertiary hyperparathyroidism. Thirty days after the parathyroidectomy, the patient returned with a significant increase in the tumour size. The suspicion of a supernumerary gland was confirmed by parathyroid scintigraphy. The treatment of brown tumour is dependent on the treatment of the hyperparathyroidism. However, curettage should be considered if a large lesion is disturbing mastication. In conclusion, this case should attract the attention of general practitioner dentists, since they may be the first professionals who have contact with the patient with a brown tumour in the jaws. Likewise, this case emphasises the importance of knowing the type of hyperparathyroidism involved to allow for effective treatment planning.

Transcription factors in parathyroid development: lessons from hypoparathyroid disorders.

Parathyroid developmental anomalies, which result in hypoparathyroidism, are common and may occur in one in 4,000 live births. Parathyroids, in man, develop from the endodermal cells of the third and fourth pharyngeal pouches, whereas, in the mouse they develop solely from the endoderm of the third pharyngeal pouches. In addition, neural crest cells that arise from the embryonic mid- and hindbrain also contribute to parathyroid gland development. The molecular signaling pathways that are involved in determining the differentiation of the pharyngeal pouch endoderm into parathyroid cells are being elucidated by studies of patients with hypoparathyroidism and appropriate mouse models. These studies have revealed important roles for a number of transcription factors, which include Tbx1, Gata3, Gcm2, Sox3, Aire1 and members of the homeobox (Hox) and paired box (Pax) families.