Ann Thorac Surg 2001;71:1697-1698
© 2001 The Society of Thoracic Surgeons
Case report
Thoracoscopic resection of an ectopic intrathoracic goiter
Sean C. Grondin, MDa,
Percival Buenaventura, MDa,
James D. Luketich, MDa
a The Mark Ravitch/Leon C. Hirsch Center for Minimally Invasive Surgery and the Section of Thoracic Surgery, Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
Accepted for publication June 21, 2000.
Address reprint request to Dr Luketich, Section of Thoracic Surgery, University of Pittsburgh Medical Center, C-800 Presbyterian University Hospital, 200 Lothrop St, Suite C 800 PUH, Pittsburgh, PA 15213–3221
e-mail: luketichjd{at}msx.upmc.edu
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Abstract
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We report a case of an ectopic intrathoracic goiter in a 79-year-old human. This uncommon finding presented as a symptomatic paratracheal mass that was resected using thoracoscopic techniques without complication.
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Introduction
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Mediastinal thyroid neoplasms are uncommon tumors that account for approximately 6% of mediastinal masses in adults [1]. Most of these tumors arise secondary to downward growth into the superior mediastinum from the thyroid gland in the neck (i.e., substernal goiter). Rarely, an ectopic thyroid tumor develops in the thorax distinct from the cervical thyroid gland. We describe a case of an ectopic superior mediastinal thyroid tumor successfully resected via a thoracoscopic approach.
The patient, a 79-year-old woman, presented with a one month history of progressive upper back pain. Her past medical history was significant for hypertension and stable coronary artery disease. Physical examination was unremarkable. Bloodwork, including thyroid function studies, was normal. A chest roentgenogram did not demonstrate any significant abnormalities. Computed tomography (CT) of the chest demonstrated a 3 x 1.5 cm high attenuation mass within the superior mediastinum located between the right subclavian vein and brachiocephalic artery with no evidence of invasion or adenopathy (Fig 1). A sestamibi thyroid scan demonstrated a normal cervical thyroid gland with separate uptake in the right upper mediastinum at the site of the mediastinal lesion (Fig 2). Following a satisfactory preoperative evaluation which included a negative stress thallium test, a thoracoscopic resection was planned.
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Fig 1. Computed tomography (CT) of the chest demonstrating high attenuation mass within the superior mediastinum between the right subclavian vein and brachiocephalic artery.
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Fig 2. Sestamibi thyroid scan demonstrating a normal cervical thyroid gland with separate uptake in the right upper mediastinum at the site of the mediastinal mass.
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At the time of surgery, bronchoscopy was normal. A double lumen endotracheal tube was placed and the patient positioned in a right lateral decubitus position. A video-assisted approach was chosen using four access ports (three 5 mm and one 10 mm port) carefully positioned in the upper thorax near the axilla to allow visualization of the paratracheal and upper parasternal areas. Dissection posterior to the superior vena cava was performed taking care not to injure the phrenic nerve. Dissection around the right tracheoesophageal groove identified one paratracheal lymph node that was sampled and found to be pathologically negative. A well-encapsulated mass that corresponded to the mass noted on preoperative CT scan was subsequently mobilized. One major feeding vessel arising from the right innominate artery was isolated, clipped, and divided. There was no cervical extension. The mass was removed en bloc without complication. Postoperatively, the patient had an uncomplicated course and was discharged on postoperative day two. The patient was found to be asymptomatic with resolution of her back pain at 1 and 6 months postoperatively. Final pathologic assessment confirmed the mass to be multinodular thyroid tissue.
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Comment
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Ectopic intrathoracic goiters account for less than 1% of all mediastinal masses [1]. Ectopic growths can be distinguished from secondary goiters by the following criteria: the ectopic tumor derives its blood supply from intrathoracic vessels rather than cervical arteries, the cervical thyroid gland is normal or absent with no history of surgery, the cervical thyroid gland does not have a similar pathologic process as the ectopic tumor, and no history or evidence of malignancy is documented [2]. On careful review, the vast majority of mediastinal goiters will not fulfill these criteria and are found to be secondary goiters.
Frequently, patients with intrathoracic goiter are asymptomatic with the tumors reported as an incidental finding on chest roentgenogram. Occasionally, compression from a slow growing tumor causes tracheal compression resulting in stridor, or esophageal compression resulting in dysphagia. Thyrotoxicosis is uncommon [3]. Imaging studies such as chest roentgenogram and chest CT usually demonstrate a sharply circumscribed mass, most commonly on the right side. The diagnosis of intrathoracic thyroid goiter can be confirmed using thyroid scanning studies that demonstrate functioning thyroid tissue in the mediastinum distinct from the cervical thyroid gland [4]. Actual classification of an ectopic goiter must be confirmed at surgery to fulfill the above criteria.
In most instances, an intrathoracic goiter can be observed in an asymptomatic patient with no evidence of a functioning cervical thyroid gland on thyroid scan. If the patient is symptomatic, the intrathoracic lesion should be resected in order to rule out malignancy and to guard against the potential for an enlarging tumor to compress adjacent structures [5]. In the case presented, the patient was symptomatic with normal cervical gland function, therefore, resection was performed. Given the location of the tumor, thoracoscopic removal was the technique of choice.
Thoracoscopy has been described as useful in both the diagnosis and resection of mediastinal masses [6]. This technique is well suited for biopsy and resection of mediastinal lesions such as the paratracheal tumor that was described. Improved visibility and low morbidity make thoracoscopy the technique of choice in selected patients. Key elements in the dissection include isolation and ligation of the arterial supply and preservation of adjacent nerves such as the phrenic and vagus nerves. Hemostasis during the dissection is essential and can usually be accomplished by removing the tumor en bloc and avoiding dissection onto the vascular tumor surface.
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References
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Luketich J.D., Ginsberg R.J. The current management of patients with mediastinal tumors. In: Cameron J.L., Balch C.M., Mannick J.A., et al. , eds. . Advances in surgery. St Louis: Mosby-Year Book, 1997:311-322.
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Abstract
Introduction
