Eur J Cardiothorac Surg 2006;30:808-810
© 2006 Elsevier Science NL
Recurrent hyperparathyroidism: a sixth mediastinal parathyroid gland
Bertrand Marcheix,
Laurent Brouchet,
Jean Berjaud,
Marcel Dahan*
Department of Thoracic Surgery, Rangueil-Larrey University Hospital, TSA 300 30, 24, chemin de Pouvourville, 31059 Toulouse, Cedex 9, France
Received 19 May 2006;
received in revised form 24 June 2006;
accepted 3 July 2006.
* Corresponding author. Tel.: +33 567 771 803; fax: +33 567 771 483. (Email: dahan.m{at}chu-toulouse.fr).
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Abstract
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We present the case of a 71-year-old woman with recurrent hyperparathyroidism. She underwent first a subtotal resection of the parathyroid glands associated with subtotal thyroidectomy in the setting of primary hyperparathyroidism and multi nodular thyroid. Pathologic findings were consistent with hyperplasia and demonstrated a fifth parathyroid gland in the thyroid. Two years later, the patient presented recurrent hyperparathyroidism associated with terminal renal insufficiency, fusion of Sesta Mibi scintigraphy and CT scan demonstrated a sixth mediastinal parathyroid gland in the aorto pulmonary window. Despite videomediastinoscopic attempts, resection was performed through manubriotomy approach. Pathologic findings demonstrated a parathyroid adenoma.
Key Words: Hyperparathyroidism • Parathyroid gland • Adenoma • Hyperplasia • Manubriotomy • Videomediastinoscopy
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1. Introduction
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Despite progresses in nuclear medicine and morphological imaging, recurrence of hyper parathyroidism remains one of the most difficult situations a surgeon may encounter because of eminently variable anatomy of parathyroid glands. The localization of the responsible parathyroid tissue and the establishment of relevant therapeutic strategy are the two crucial steps of the surgical treatment. We report the case of a sixth mediastinal parathyroid gland responsible for the recurrence of secondary hyperparathyroidism.
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2. Case report
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A 71-year-old woman presented biochemical evidence of primary hyperparathyroidism. Her blood level of parathyroid hormone was 973 pg/ml (normal < 85) and her serum Ca2+ was 2.5 mmol/l (2.2–2.6). She was operated on. As perioperative pathological findings demonstrated hyperplasia, subtotal parathyroidectomy was performed. Half of the left inferior parathyroid gland was left in place. As the thyroid gland was found abnormal, subtotal thyroidectomy was performed in the same operating time. Pathological findings confirmed hyperplasia, and demonstrated furthermore a fifth hyperplasic parathyroid gland in the thyroid gland. The serum Ca2+ level quickly returned to a normal value.
Two years later our patient returned to our institution with elevated serum calcium level and worsening renal function. She had required hemodialysis for 1 year. Her serum Ca2+ was 2.5 mmol/l (2.2–2.6) and a parathyroid hormone (PTH) assay was 973 pg/ml (normal < 85). Sesta-Mibi scintigraphy demonstrated a focus of intense tracer localization in the mediastinum that was consistent with a sixth hyperfunctioning parathyroid gland, there was not any cervical localization (Fig. 1c–e). CT (Fig. 1a–c) and MR (Fig. 1f) scans localized the parathyroid tissue in the aorto pulmonary window. She was taken to the operating room for excision of the mediastinal parathyroid gland. Despite videomediastinoscopic attempts, median manubriotomy had to be performed. The parathyroid gland was found in the aorto pulmonary window as observed on morphological examinations (Fig. 1g). Sharp dissection was used to totally excise the gland with an intact capsule (Fig. 1h). A frozen section confirmed that the mass consisted of parathyroid tissue. The patient tolerated the procedure well and had an uncomplicated postoperative course. The final pathologic examination confirmed that the lesion was a parathyroid adenoma. Six months after the surgery, her serum Ca2+ and PTH levels have returned to normal values. The patient is dialyzed three times a week and she is doing well.
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Fig. 1. (a–c) Computed tomography scan, axial (a), coronal (b), and sagital (c) views with mediastinal settings. The white arrows demonstrated abnormal tumor between the aorta and the pulmonary artery. (d–f) Sesta-Mibi scintigraphy with axial (d), coronal (e), and sagital (f) views combined with computed tomography scan demonstrating intense positive tracer between the aorta and the pulmonary artery. (g) Magnetic resonance imaging demonstrating abnormal tumor between the aorta and the pulmonary artery. (h) Perioperative view demonstrating the ectopic parathyroid gland (yellow arrow) between the aorta (white arrow) and the pulmonary artery (blue arrow). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
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3. Discussion
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Recurrence of hyperparathyroidism remains one of the most difficult situations a surgeon may encounter and systematic assessment of blood levels of Ca2+ and of PTH, 1 month after the initial treatment of hyperparathyroidism may be interesting to detect early failure of surgical management. Reasons for failed parathyroid surgical treatment include ectopic locations, parathyreomatosis and graft-dependent hypercalcemia. Parathyroid cancer remains rare. Ectopic locations represent 75% of the cases while supernumerary glands represent 39% of the cases. Parathyroid glands are located in the mediastinum in as many as 25% of patients most of the time within thymic tissue but only 2% cannot be removed through a cervical approach [1]. Ectopic glands are most of the time intrathymic, but they may also have an extrathymic mediastinal location. The aortopulmonary window would represent 5% of these cases. Our patient had at the same time a supernumerary parathyroid gland, which was located in aorto pulmonary window moreover it was a sixth parathyroid gland.
Preoperative localization of the responsible parathyroid tissue is the first step to establish surgical strategy. Technical advances in nuclear medicine and radiology have made it possible to combine morphological and functional studies. Thus, convergent positivity of, at least, two studies allowed surgery to focus on the positive area. Sesta-MIBI scintigraphy is the most sensitive noninvasive study to detect pathological glands (69–77%) but it is insufficient to precisely localize a thoracic parathyroid gland [2]. CT scans and even MR scans with multiplanar reconstruction are much more relevant for precise location but are unable to affirm the parathyroid nature of the abnormal structure. The combination of these two examinations was very helpful in the case of our patient and allowed to identify the supernumerary and ectopic sixth gland in the aortapulmonary window.
Angiographic ablation of this lesion could have avoided surgery but this technique is reported to have a success rate of only 60% and may be associated with neurologic complications [3]. Alcoolization of parathyroid glands has been presented as an alternative to surgery but this mediastinal location could not be approached percuteanously. Video assisted thoracoscopic surgery procedures or videomediastinoscopic procedures have been proposed to remove mediastinal parathyroid lesions [3,4]. Despite videomediastinoscopic attempts videomediastinoscopic excision was not possible and the best therapeutic option was median manubriotomy.
As a conclusion, mediastinal supernumerary parathyroid gland may be responsible for recurrence of hyperparathyroidism. The combination of morphological and functional preoperative examination is very useful to establish surgical strategy and may avoid the use of perioperative detection. Manubriotomy had to be performed because of impossibility to find the parathyroid tissue through videomediastinoscopic approach because of location between the aorta and the pulmonary artery.
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References
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- Nudelman IL, Deutsch AA, Reiss R. Primary hyperparathyroidism due to mediastinal parathyroid adenoma. Int Surg 1987;72:104-108.[Medline]
- Shen W, Duren M, Morita E, Higgins C, Duh QY, Siperstein AE, Clark OH. Reoperation for persistent or recurrent primary hyperparathyroidism. Ach Surg 1996;131:861-867.
- Heller HJ, Miller GL, Erdman WA, Snyder WH, Breslau NA. Angiographic ablation of mediastinal parathyroid adenomas, local experience and review of the literature. Am J Med 1994;97:529-534.[CrossRef][Medline]
- Medrano C, Hazelrigg SR, Landreneau RJ, Boley TM, Shawgo T, Grasch A. Thoracoscopic resection of ectopic parathyroid glands. Ann Thorac Surg 2000;69:221-223.[Abstract/Free Full Text]
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Abstract
1. Introduction
