Clinical Review & Education
JAMA Surgery Clinical Challenge
Anterior Mediastinal Mass Daniel J. Gross, MD; Gainosuke Sugiyama, MD; Antonio Alfonso, MD
A Computed tomographic scan of chest
B
Gross findings following sternotomy
Figure. A, Computed tomographic scan of the chest revealing a mediastinal mass. B, Intraoperative dissection following median sternotomy.
An asymptomatic 47-year-old woman underwent a radiographic screening to rule out tuberculosis prior to volunteering at her local hospital. The incidental finding of a mediastinal mass prompted a referral to her primary care physician, who elicited from the patient some complaints of mild but worsening orthopnea that was exacerbated when she would lie down. She denied any recent weight loss, muscle weakness, or diplopia. Her surgical history was significant for having undergone a cesarean section. She denied any radiation exposure. A computed tomographic scan of the chest was obtained (Figure, A), and the patient was referred to surgery for evaluation. A physical examination identified a midline trachea, no significant thyromegaly in the neck, no significant lymphadenopathy, and no additional significant findings. The patient was taken to the operating room for surgery to remove the mass (with gross findings as seen in Figure, B).
jamasurgery.com
WHAT IS YOUR DIAGNOSIS?
A. Thymoma B. Teratoma C. Lymphoma D. Substernal goiter
(Reprinted) JAMA Surgery Published online February 3, 2016
Copyright 2016 American Medical Association. All rights reserved.
Downloaded From: http://archsurg.jamanetwork.com/ by a University of Pittsburgh User on 02/16/2016
E1
Clinical Review & Education JAMA Surgery Clinical Challenge
Diagnosis D. Substernal goiter
Discussion The anterior mediastinum is the most common site of mediastinal masses, which are most commonly goiters, thymomas, teratomas, mediastinal metastases, or lymphomas, with clinical and radiologic features aiding in the diagnosis.1 Substernal goiter has been the focus of surgical luminaries from Kocher2 to Lahey3 since its first characterization in 1749.4 Its pathophysiology is surmised to stem from a deficiency in iodine that can lead to decreased thyronine levels and a compensatory elevation in thyrotropin, thus causing thyroid hypertrophy and the development of goiter.5 The classic presentation is that of a woman in her fifth decade with an anterior mediastinal mass arising from the lower pole of the thyroid gland, supplied by the inferior thyroid artery. The theory behind this pattern of growth is the presence of anatomical barriers around the gland, superiorly by the thyroid and cricoid cartilage, posteriorly by the prevertebral fascia, and anteriorly by the strap muscles, leaving only the inferior area without a barrier to growth. Furthermore, the negative intrathoracic pressure accompanying swallowing and aided by gravity is thought to slowly bring an enlarging goiter to its substernal resting place.5 The majority of goiters are benign and are most commonly of the nodular goiter subtype.5 ARTICLE INFORMATION
REFERENCES
Author Affiliations: Department of Surgery, Downstate Medical Center, State University of New York, Brooklyn.
1. Carter BW, Marom EM, Detterbeck FC. Approaching the patient with an anterior mediastinal mass: a guide for clinicians. J Thorac Oncol. 2014;9(9 suppl 2):S102-S109.
Corresponding Author: Daniel J. Gross, MD, Department of Surgery, Downstate Medical Center, State University of New York, 450 Clarkson Ave, Brooklyn, NY 11203 ([email protected]). Section Editor: Pamela A. Lipsett, MD, MHPE. Published Online: February 3, 2016. doi:10.1001/jamasurg.2015.4432. Conflict of Interest Disclosures: None reported. Additional Contributions: We would like to acknowledge the efforts of Timothy Carter, MD, at the Department of Cardiothoracic Surgery of the Hospital of the University of Pennsylvania, Philadelphia, for his in help in editing the manuscript. He did not receive any compensation. We thank the patient for granting permission to publish this information.
E2
Most patients tend to be asymptomatic, with only the occasional complaint of dysphagia related to mass effect. Computed tomography of the neck and chest is helpful in discerning anatomic relationships between the mass and adjacent structures, and in aiding preoperative planning.6 The treatment of choice for substernal goiter is surgical excision.5 The technical considerations of surgery deviate only slightly from traditional thyroidectomy; careful dissection is essential in locating the recurrent laryngeal nerve. With planar dissection, the goiter is then “delivered” into the cervical region.7 Traditional predictors of substernal goiters that require sternotomy include invasive thyroid cancers, a previous thyroidectomy, superior vena cava syndrome, isolated primary mediastinal tumors, a posterior mediastinal location, extension below the aortic arch, a gland mass of greater than 260 g, or an intrathoracic independent blood supply.7,8 Finally, while rare, tracheomalacia must be considered; although compression of the trachea can weaken the cartilage initially, the trachea may become dependent on the mass as a buttress.9 Following mass excision, airway collapse and negative-pressure pulmonary edema are chief concerns. These are best avoided with prolonged intubation and, occasionally, by a tracheostomy.9 Repair by tracheopexy with various meshes has been described.9 Novel approaches involving video-assisted thoracoscopic resection of mediastinal goiters have gained acceptance and represent an innovative solution to spare selected patients’ from undergoing a sternotomy.10
2. Kocher T. Bericht uber ein sweites tousend kroptexcissionen. Arch Clin Chir. 1901;64:454-461. 3. Lahey FH. Intrathoracic goiter. JAMA. 1939;113(2): 1098-1105. doi:10.1001/jama.1939 .02800370014004. 4. von Haller A. Disputationes Anatomica Selectae. Göttingen, Germany: Vandenhoeck; 1749:96. 5. Newman E, Shaha AR. Substernal goiter. J Surg Oncol. 1995;60(3):207-212. 6. Malvemyr P, Liljeberg N, Hellström M, Muth A. Computed tomography for preoperative evaluation of need for sternotomy in surgery for retrosternal goitre. Langenbecks Arch Surg. 2015;400(3): 293-299.
7. Shaha AR, Alfonso AE, Jaffe BM. Operative treatment of substernal goiters. Head Neck. 1989;11 (4):325-330. 8. Hajhosseini B, Montazeri V, Hajhosseini L, Nezami N, Beygui RE. Mediastinal goiter: a comprehensive study of 60 consecutive cases with special emphasis on identifying predictors of malignancy and sternotomy. Am J Surg. 2012;203 (4):442-447. 9. Meurala H, Halttunen P, StandertskjöldNordenstam CG, Keskitalo E. Surgical support of collapsing intrathoracic tracheomalacia after thyroidectomy. Acta Chir Scand. 1982;148(2):127-129. 10. Grondin SC, Buenaventura P, Luketich JD. Thoracoscopic resection of an ectopic intrathoracic goiter. Ann Thorac Surg. 2001;71(5):1697-1698.
JAMA Surgery Published online February 3, 2016 (Reprinted)
Copyright 2016 American Medical Association. All rights reserved.
Downloaded From: http://archsurg.jamanetwork.com/ by a University of Pittsburgh User on 02/16/2016
jamasurgery.com
JAMA Surgery Clinical Challenge
Anterior Mediastinal Mass Daniel J. Gross, MD; Gainosuke Sugiyama, MD; Antonio Alfonso, MD
A Computed tomographic scan of chest
B
Gross findings following sternotomy
Figure. A, Computed tomographic scan of the chest revealing a mediastinal mass. B, Intraoperative dissection following median sternotomy.
An asymptomatic 47-year-old woman underwent a radiographic screening to rule out tuberculosis prior to volunteering at her local hospital. The incidental finding of a mediastinal mass prompted a referral to her primary care physician, who elicited from the patient some complaints of mild but worsening orthopnea that was exacerbated when she would lie down. She denied any recent weight loss, muscle weakness, or diplopia. Her surgical history was significant for having undergone a cesarean section. She denied any radiation exposure. A computed tomographic scan of the chest was obtained (Figure, A), and the patient was referred to surgery for evaluation. A physical examination identified a midline trachea, no significant thyromegaly in the neck, no significant lymphadenopathy, and no additional significant findings. The patient was taken to the operating room for surgery to remove the mass (with gross findings as seen in Figure, B).
jamasurgery.com
WHAT IS YOUR DIAGNOSIS?
A. Thymoma B. Teratoma C. Lymphoma D. Substernal goiter
(Reprinted) JAMA Surgery Published online February 3, 2016
Copyright 2016 American Medical Association. All rights reserved.
Downloaded From: http://archsurg.jamanetwork.com/ by a University of Pittsburgh User on 02/16/2016
E1
Clinical Review & Education JAMA Surgery Clinical Challenge
Diagnosis D. Substernal goiter
Discussion The anterior mediastinum is the most common site of mediastinal masses, which are most commonly goiters, thymomas, teratomas, mediastinal metastases, or lymphomas, with clinical and radiologic features aiding in the diagnosis.1 Substernal goiter has been the focus of surgical luminaries from Kocher2 to Lahey3 since its first characterization in 1749.4 Its pathophysiology is surmised to stem from a deficiency in iodine that can lead to decreased thyronine levels and a compensatory elevation in thyrotropin, thus causing thyroid hypertrophy and the development of goiter.5 The classic presentation is that of a woman in her fifth decade with an anterior mediastinal mass arising from the lower pole of the thyroid gland, supplied by the inferior thyroid artery. The theory behind this pattern of growth is the presence of anatomical barriers around the gland, superiorly by the thyroid and cricoid cartilage, posteriorly by the prevertebral fascia, and anteriorly by the strap muscles, leaving only the inferior area without a barrier to growth. Furthermore, the negative intrathoracic pressure accompanying swallowing and aided by gravity is thought to slowly bring an enlarging goiter to its substernal resting place.5 The majority of goiters are benign and are most commonly of the nodular goiter subtype.5 ARTICLE INFORMATION
REFERENCES
Author Affiliations: Department of Surgery, Downstate Medical Center, State University of New York, Brooklyn.
1. Carter BW, Marom EM, Detterbeck FC. Approaching the patient with an anterior mediastinal mass: a guide for clinicians. J Thorac Oncol. 2014;9(9 suppl 2):S102-S109.
Corresponding Author: Daniel J. Gross, MD, Department of Surgery, Downstate Medical Center, State University of New York, 450 Clarkson Ave, Brooklyn, NY 11203 ([email protected]). Section Editor: Pamela A. Lipsett, MD, MHPE. Published Online: February 3, 2016. doi:10.1001/jamasurg.2015.4432. Conflict of Interest Disclosures: None reported. Additional Contributions: We would like to acknowledge the efforts of Timothy Carter, MD, at the Department of Cardiothoracic Surgery of the Hospital of the University of Pennsylvania, Philadelphia, for his in help in editing the manuscript. He did not receive any compensation. We thank the patient for granting permission to publish this information.
E2
Most patients tend to be asymptomatic, with only the occasional complaint of dysphagia related to mass effect. Computed tomography of the neck and chest is helpful in discerning anatomic relationships between the mass and adjacent structures, and in aiding preoperative planning.6 The treatment of choice for substernal goiter is surgical excision.5 The technical considerations of surgery deviate only slightly from traditional thyroidectomy; careful dissection is essential in locating the recurrent laryngeal nerve. With planar dissection, the goiter is then “delivered” into the cervical region.7 Traditional predictors of substernal goiters that require sternotomy include invasive thyroid cancers, a previous thyroidectomy, superior vena cava syndrome, isolated primary mediastinal tumors, a posterior mediastinal location, extension below the aortic arch, a gland mass of greater than 260 g, or an intrathoracic independent blood supply.7,8 Finally, while rare, tracheomalacia must be considered; although compression of the trachea can weaken the cartilage initially, the trachea may become dependent on the mass as a buttress.9 Following mass excision, airway collapse and negative-pressure pulmonary edema are chief concerns. These are best avoided with prolonged intubation and, occasionally, by a tracheostomy.9 Repair by tracheopexy with various meshes has been described.9 Novel approaches involving video-assisted thoracoscopic resection of mediastinal goiters have gained acceptance and represent an innovative solution to spare selected patients’ from undergoing a sternotomy.10
2. Kocher T. Bericht uber ein sweites tousend kroptexcissionen. Arch Clin Chir. 1901;64:454-461. 3. Lahey FH. Intrathoracic goiter. JAMA. 1939;113(2): 1098-1105. doi:10.1001/jama.1939 .02800370014004. 4. von Haller A. Disputationes Anatomica Selectae. Göttingen, Germany: Vandenhoeck; 1749:96. 5. Newman E, Shaha AR. Substernal goiter. J Surg Oncol. 1995;60(3):207-212. 6. Malvemyr P, Liljeberg N, Hellström M, Muth A. Computed tomography for preoperative evaluation of need for sternotomy in surgery for retrosternal goitre. Langenbecks Arch Surg. 2015;400(3): 293-299.
7. Shaha AR, Alfonso AE, Jaffe BM. Operative treatment of substernal goiters. Head Neck. 1989;11 (4):325-330. 8. Hajhosseini B, Montazeri V, Hajhosseini L, Nezami N, Beygui RE. Mediastinal goiter: a comprehensive study of 60 consecutive cases with special emphasis on identifying predictors of malignancy and sternotomy. Am J Surg. 2012;203 (4):442-447. 9. Meurala H, Halttunen P, StandertskjöldNordenstam CG, Keskitalo E. Surgical support of collapsing intrathoracic tracheomalacia after thyroidectomy. Acta Chir Scand. 1982;148(2):127-129. 10. Grondin SC, Buenaventura P, Luketich JD. Thoracoscopic resection of an ectopic intrathoracic goiter. Ann Thorac Surg. 2001;71(5):1697-1698.
JAMA Surgery Published online February 3, 2016 (Reprinted)
Copyright 2016 American Medical Association. All rights reserved.
Downloaded From: http://archsurg.jamanetwork.com/ by a University of Pittsburgh User on 02/16/2016
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