RESUMEN
UNLABELLED: 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.
Asunto(s)
Adenoma/diagnóstico por imagen , Adenoma/cirugía , Neoplasias de las Paratiroides/diagnóstico por imagen , Neoplasias de las Paratiroides/cirugía , Paratiroidectomía/métodos , Tecnecio Tc 99m Sestamibi , Tomografía Computarizada de Emisión de Fotón Único/métodos , Adenoma/embriología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de las Paratiroides/embriología , Cuidados Preoperatorios/métodos , Pronóstico , Radiografía , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
A patient underwent reexploration for a parathyroid adenoma; following identification of four normal glands in the cervical region, the mediastinum was entered, and an intrathymic lipoadenoma was excised. These very rare tumors have been associated with hypercalcemia in approximately half of the previously reported cases; however, none has previously been described as occurring entirely in the mediastinum.
Asunto(s)
Adenoma/patología , Coristoma/patología , Lipoma/patología , Neoplasias del Mediastino/patología , Glándulas Paratiroides , Neoplasias del Timo/patología , Adenoma/embriología , Adulto , Femenino , Hamartoma/patología , Humanos , Ganglios Linfáticos/patología , Masculino , Persona de Mediana Edad , Neoplasias de las Paratiroides/embriología , Neoplasias de las Paratiroides/patología , Timo/patologíaRESUMEN
Mediastinal adenomas form about 10 % of all parathyroid adenomas, and are only very rarely visualized in standard pulmonary radiograms. This was the case however in a 54-year-old woman with hyperparathyroidism, chronic renal insufficiency, and an anterosuperior mediastinal tumor. After surgical excision by sternotomy the mass was found to be a large parathyroid adenoma weighing 105 g and measuring 8 cm in diameter. The authors discuss the problems raised by mediastinal adenomas and review the cases reported in the published literature.