Persistent primary hyperparathyroidism: an uncommon location for an ectopic gland - Case report and review

Abstract

SUMMARYPrimary hyperparathyroidism (PHPT) is a common endocrine disorder that mainly affects middleaged women. Patients are usually asymptomatic. The disease might be ascribable to hyperplasia, carcinoma, and single or multiple adenomas. PHPT may be sporadic or familial, the latter comprising multiple endocrine neoplasia type 1 or 2A, familial benign hypocalciuria hypercalcemia, and hyperparathyroidism-jaw tumor syndrome. The most common causes for persistent PHPT are multiglandular disease, and missed abnormal ectopic or orthotopic parathyroid glands. Ima ging localization studies should precede a new surgical intervention. Ectopic parathyroid glands are rarely located at the aortopulmonary window. For diagnosis confirmation, Tc-sestamibi SPECT/CT seems to be an advantageous test. Another possibility is to perform 99m Tc-sestamibi followed by thoracic CT or MRI. Parathyroidectomy may be performed by means of median sternotomy, thoracotomy, or video-assisted thoracoscopy. We describe a case of persistent primary hyperparathyroidism due to the presence of an ectopic parathyroid gland found at the aortopulmonary window. As the investigation necessary to clarify the etiology of recurrent nephrolithiasis proceeded, the diagnosis of PHPT was determined. The patient underwent subtotal parathyroi dectomy; nevertheless, PHPT persisted. Genetic syndromes that could account for this condition were excluded. Imaging studies available at that time were not able to locate abnormal glands; moreover, the patient refused to undergo surgical exploration. Later, the patient underwent 99m Tc-sestamibi SPECT/CT, which revealed a parathyroid gland at the aortopulmonary window. Arq Bras Endocrinol Metab. 2012;56(6):393-403 SUMÁRIO O hiperparatiroidismo primário (HPP) é uma endocrinopatia frequente que afeta maioritariamente mulheres de meia-idade e é geralmente assintomática. A doença pode ser atribuível a hiperplasia, carcinoma, adenomas únicos ou múltiplos. O HPP inclui formas esporádicas e familiares. As formas familiares englobam neoplasia endócrina múltipla tipo 1 ou 2A, hipercalcemia hipocalciúrica familiar e síndrome hiperparatiroidismo/tumor mandibular-maxilar. As causas mais frequentes de HPP persistente são a presença de doença multiglandular ou de paratiroide anômala ectópica ou ortotópica não identificada previamente. É recomendável que a localização imagiológica preceda a reintervenção cirúrgica. A janela aortopulmonar é uma localização ectópica rara, sendo o 99m Tcsestamibi SPECT/TC um exame de confirmação vantajoso ou, alternativamente o 99m Tc-sestamibi seguido de TC ou RM torácica. A paratiroidectomia pode ser efetuada por meio de esternotomia mediana, toracotomia ou toracoscopia videoassistida. Descrevemos um caso de HPP persistente atribuível à presença de uma glândula paratiroide ectópica localizada à janela aortopulmonar. O diagnóstico de HPP foi estabelecido na sequência da investigação requisitada para esclarecimento etiológico da nefrolitíase recidivante constatada nessa doente. Foi submetida à paratiroidec...

Parathyroid adenoma localization with 99mTc-sestamibi SPECT/CT

“…Ruf et al One clear benefit of SPECT/CT has been for surgical planning based on precise preoperative parathyroid adenoma localization [10,[47][48][49][50][51][52][53][54][55]. Differentiation between adenomas originating from superior glands and those originating from inferior glands is illustrated on SPECT/CT scans with ectopic inferior adenomas positioned anteriorly in the mediastinum and ectopic superior glands seen in more posterior locations [2].…”

Endocrine Scintigraphy with Hybrid SPECT/CT

“…Overall there appears to be a sequential step-up in sensitivity between planar (59%-76%), SPECT (67%-97%) and SPECT/CT (77%-100%) imaging techniques (235,239,244). One of the major advantages of SPECT/CT has been for preoperative identification and localization of adenomas in unusual retrotracheal sites and of ectopic parathyroid adenomas (232) (230,(251)(252)(253)(254)(255)(256)(257)(258)(259). The rates of ectopic locations vary between 10%-20% in SPECT/CT cohorts (231, 232, 234 -246).…”

Incidental Detection of Parathyroid Adenoma on Somatostatin Receptor PET/CT and Incremental Role of 18F-Fluorocholine PET/CT in MEN1 Syndrome

“…Noninvasive imaging including ultrasonography (USG), technetium-99m sestamibi, computed tomography (CT) scan, and magnetic resonance imaging (MRI) are being used before parathyroid surgery. Though in MEN1 syndrome the likely multiple parathyroid gland involvement makes it logical to perform a four-gland exploration at initial surgery, thus regarding role of preoperative imaging, one of the indications is to rule out presence of an ectopic adenoma which can be missed during the initial exploration as shown by Gouveia S et al [9]. For the management of hyperparathyroidism, surgical removal of the abnormally overactive parathyroid glands is the definitive treatment, but it is controversial whether to perform subtotal (3.5 glands) or total parathyroidectomy with each approach having its advantage and disadvantages.…”