Ann Thorac Surg 2015;100:2333–6
Comment In this case, we report the use of the Hemolung RAS as a prolonged bridge to lung transplantation, and the first use of the Hemolung as a bridge to redo lung transplantation. Additionally, this is the first use of the device in a patient in the United States. A handful of case series have described the use of the Hemolung for up to 8 days in patients with chronic obstructive pulmonary disease, but reports describing its use in patients requiring respiratory support for other conditions are sparse [5, 6]. Although ECMO has served as an adequate support to bridge patients to lung transplantation, its use has been Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
2333
limited by the large cannulas and high circulating volumes required, inflammatory response in the presence of a large-area membrane oxygenator, and risks of bleeding and thrombolytic adverse events [1, 2]. The Hemolung offers an attractive and less invasive alternative for CO2 removal that can be implemented at the bedside. It could be used in some patients waiting for lung transplantation to reduce the risk of adverse events. Further study of the potential benefits of extracorporeal CO2 removal as an alternative to ECMO is both important and warranted, especially in patients who require mechanical support as a bridge to lung transplantation including redo cases. The authors wish to thank ALung Technologies for providing the Hemolung device and Shannon Wyszomierski for editorial support.
References 1. Bermudez CA, Rocha RV, Zaldonis D, et al. Extracorporeal membrane oxygenation as a bridge to lung transplant: midterm outcomes. Ann Thorac Surg 2011;92:1226–31; discussion 31–2. 2. Javidfar J, Bacchetta M. Bridge to lung transplantation with extracorporeal membrane oxygenation support. Curr Opin Organ Transplant 2012;17:496–502. 3. Kawut SM, Lederer DJ, Keshavjee S, et al. Outcomes after lung retransplantation in the modern era. Am J Respir Crit Care Med 2008;177:114–20. 4. Batchinsky AI, Jordan BS, Regn D, et al. Respiratory dialysis: reduction in dependence on mechanical ventilation by venovenous extracorporeal CO2 removal. Crit Care Med 2011;39: 1382–7. 5. Burki NK, Mani RK, Herth FJ, et al. A novel extracorporeal CO(2) removal system: results of a pilot study of hypercapnic respiratory failure in patients with COPD. Chest 2013;143: 678–86. 6. Bonin F, Sommerwerck U, Lund LW, Teschler H. Avoidance of intubation during acute exacerbation of chronic obstructive pulmonary disease for a lung transplant candidate using extracorporeal carbon dioxide removal with the Hemolung. J Thorac Cardiovasc Surg 2013;145:e43–4.
Primary Ectopic Mediastinal Goiter in a Patient With Crohn’s Disease Presenting as Myasthenia Gravis Sunil Kumar, MS, Mahesh Sultania, MS, Shivam Vatsal, MS, and M. C. Sharma, MD Department of Surgical Oncology, Dr BRA Institute Rotary Cancer Hospital, and Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
Mediastinum is an uncommon location for ectopic goiter. Primary ectopic mediastinal goiter has been reported to present mostly with compressive symptoms. We report a case of a 62-year-old man with history of Crohn’s disease, who presented with symptoms of myasthenia gravis and was found to have an anterior mediastinal mass. The 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2015.02.116
FEATURE ARTICLES
A 3,000-U initial bolus of heparin was administered for anticoagulation and then was titrated to maintain a partial thromoboplastin time of 45 to 60 seconds. Hemolung support was initiated at 470 to 540 mL/min flow and 500 rpm motor speed, which was slowly increased to 1,000 to 1,400 rpm (Fig 2). A notable decrease in systemic CO2 levels was observed within 24 hours, with progressive decreases over 4 to 6 days (Fig 3). During support, the patient received maintenance MV with decreased oxygen requirements to maintain arterial oxygen levels above 60 mm Hg (Fig 4). He was weaned from vasopressors, which were no longer required after 4 days of support. CO2 removal averaged 93 7 mL/min during days 2 through 20 of support. Systemic CO2 levels remained below 100 mm Hg (averaging 79 9 mm Hg on days 2–20) (Fig 3). After 9 days of support, the patient was accepted as a candidate for redo lung transplantation because of his considerable clinical improvement. He was awake, could be mobilized to sit on the edge of the bed, and maintained a better fluid balance with continuous venovenous hemodiafiltration. Donor lungs became available from a donor meeting the standard criteria 20 days after the initiation of Hemolung support. Standard preservation and surgical techniques were used for transplantation. The Hemolung device was removed at the time of the transplantation, and a double lung transplantation was performed with the use of cardiopulmonary support. After transplantation, the patient’s chest was left open for 3 days because of a size mismatch. The patient required MV for 7 days immediately after the transplantation. He remained in the ICU for 12 days. Hemolung support was not required at any point after transplantation. The patient required treatment for acute cellular rejection and was discharged 89 days after transplantation with adequate lung function, in good clinical condition, and ambulating independently. The patient did not encounter airway or other respiratory adverse events and is currently active and able to walk 1.5 to 2 miles without assistance. There was significant improvement in lung function from a forced expiratory volume in 1 second of 0.92 L before transplantation to 3.05 L 9 months after transplantation. The postoperative adverse event of renal failure requiring dialysis is still present; kidney transplantation is being considered.
CASE REPORT KUMAR ET AL ECTOPIC MEDIASTINAL GOITER WITH MYASTHENIA
2334
CASE REPORT KUMAR ET AL ECTOPIC MEDIASTINAL GOITER WITH MYASTHENIA
mass was resected completely with successful outcome. On histopathologic examination this mass turned out to be colloid goiter. This is an extremely rare presentation of a primary ectopic mediastinal goiter. (Ann Thorac Surg 2015;100:2333–6) Ó 2015 by The Society of Thoracic Surgeons
T
FEATURE ARTICLES
rue primary ectopic goiters are uncommon and account for less than 1% of all goiters [1]. They have been described at different sites from foramen caecum downward in the neck, but the mediastinum is a rare site for ectopic goiters. Among the various pathologic processes presenting as mediastinal masses, ectopic goiter is still considered as a diagnostic possibility. Most of the symptoms are because of compression on the surrounding structures. Here we report a case of primary mediastinal goiter in a patient with Crohn’s disease who presented with myasthenia gravis and was managed successfully with surgical resection of the mediastinal mass. To our knowledge there has been no report of a primary mediastinal goiter presenting as myasthenia gravis in the English literature. A 62-year-old male patient with a history of Crohn’s disease on medications for last 12 years was well until he exhibited generalized weakness, difficulty in swallowing, slurring of speech, and ptosis of the right eye, which appeared gradually over a period of 2 months. The patient was diagnosed to have myasthenia gravis (Osserman grade IV) with an acetylcholine receptor autoantibody titer of 13.46 nmol/L (positive if >0.4), and the edrophonium test was also positive. The patient was then started on pyridostigmine, and his dose of prednisolone was increased. His symptoms were deteriorating, and on further investigation his computed tomography scan of the chest showed the presence of an anterior mediastinal mass (Figs 1, 2) with a provisional diagnosis of thymoma. The thyroid function test and serum markers for germ cell tumor were within normal ranges. Because the myasthenic symptoms were not adequately managed by drugs, thymectomy was planned through a midline sternotomy approach. Intraoperatively a 13- 10-cm mass (Fig 3) was present in the anterior mediastinum with multiple vessels over its surface, in close contact with the superior vena cava and the trachea, which were pushed aside but were not invaded by the tumor. The tumor appeared to be arising from the thymic location. Complete excision of the mass was done with clearance of all the intervening connective tissue until reaching the lower border of the thyroid gland in the neck. The thyroid gland appeared normal and was totally separate from the mediastinal mass. The postoperative period was uneventful, and the patient was discharged on the eighth postoperative day.
Ann Thorac Surg 2015;100:2333–6
The histopathologic report of the tumor was surprising as it revealed no thymic tissue; rather, it showed only features of an adenomatous goiter (Fig 4). There was no lymphocytic infiltration, lymphoid follicle formation, or H€ urthle cell change. The patient had remarkable improvement in myasthenic symptoms; his drug requirements for myasthenia gravis have decreased to one fourth of the preoperative doses. During the follow-up period, ultrasound of the neck showed a normal thyroid, and the thyroid function has also been normal.
Comment Accessory thyroid is the presence of thyroid tissue other than the thyroid located anterolaterally between the second and fourth tracheal cartilages. The terms ectopic and accessory thyroid have been used interchangeably in the literature. Collins [2] defined true accessory thyroid as a distinct island of thyroid tissue separate from the typical thyroid body. Lingual thyroid is the most common form of thyroid ectopy, accounting for more than 90% of cases. Extralingual thyroid tissue is commonly located along the path of the thyroglossal duct but has also been reported in distant organs. Post-mortem studies suggest that asymptomatic thyroid tissue may be found in as many as 7% to 10% of adults. Ectopic thyroid tissue may coexist with a eutopic thyroid, as seen in our patient, or may be the only functioning tissue. The mediastinum is an unusual location for accessory thyroid tissue, and primary accessory mediastinal goiters are even more uncommon. They derive their blood supply completely from intrathoracic vessels. Vadasz and Kotsis [3] suggested that the origin of mediastinal goiter could be related to increased thyroid-stimulating hormone production after cervical thyroidectomy, although in this patient there
Accepted for publication Feb 6, 2015. Address correspondence to Dr Kumar, F-23, Ansari Nagar, AIIMS, New Delhi-110029, India; e-mail: [email protected].
Fig 1. Contrast-enhanced computed tomography scan of thorax showing the mediastinal mass in an axial section.
Ann Thorac Surg 2015;100:2333–6
CASE REPORT KUMAR ET AL ECTOPIC MEDIASTINAL GOITER WITH MYASTHENIA
2335
Fig 4. Photomicrograph of the tumor showing colloid goiter in low magnification (40) on H & E (Hematoxylin & Eosin) staining.
Fig 2. Contrast-enhanced computed tomography scan of thorax showing the mass in a coronal section.
was no such history and the baseline thyroid function was normal. Mediastinal goiter can remain asymptomatic until the structures located in the thoracic inlet are compressed. The most common symptoms are dyspnea, dysphagia, cough, hoarseness, and features of superior vena cava obstruction. This patient presented with features of
FEATURE ARTICLES
Fig 3. Macroscopic view of the excised specimen showing the lobulated solid mass.
myasthenia gravis, which was progressing even on drug therapy. We could not find any report of mediastinal goiter presenting as myasthenia in the literature, although there have been studies describing association of myasthenia with thyropathies, including nontoxic goiter, but all of them were in normally located cervical thyroid glands. There is no clinical correlation between myasthenia symptoms and thyroid dysfunction, nor a significant influence on myasthenic symptoms when the endocrine disorders improve [4]. Marin o and colleagues [5] suggested that acetylcholine receptor autoantibodies were more common in non–autoimmune thyroid disease than in autoimmune thyroid disease. Myasthenia gravis has been reported to be associated with both ulcerative colitis and Crohn’s disease, and is thought to be related to the presence of autoantibodies [6, 7]. This patient had a longstanding history of Crohn’s disease that was controlled with drugs, but the remarkable improvement in myasthenic symptoms after surgical resection of the mediastinal mass points toward a role of this mass in the disease pathology, making the existence of a random association less likely. Although the provisional preoperative diagnosis in this patient was thymoma, we could not find any thymic tissue in the resected specimen. Spinner and associates [8] described the entity called intrathymic thyroid, in which thyroid tissue was closely associated with atrophic thymic tissue, but none of the described patients presented with myasthenic symptoms. A possibility of autoantibody mechanism for the myasthenia may be present in this patient, as has been proposed about the association between myasthenia and non–autoimmune thyroid disorders. But it remains a hypothesis, and further immunopathologic studies will be required to understand this association. Thyroid scintigraphy is highly sensitive and specific for detecting normal and ectopic thyroid tissues. It should be done in cases when a mass is located in the superior mediastinum in continuity with the cervical thyroid, but it is generally not performed for masses that are lying in the
2336
CASE REPORT LONIE ET AL MINIMALLY INVASIVE TRACHEAL RESECTION
lower mediastinum because of a low index of suspicion, as was the scenario in this case. Based on the location, computed tomography–guided fine-needle aspiration or transbronchial needle aspiration can be used to obtain tissue diagnosis, but in almost all the reports the final diagnosis was made after surgical resection. Although there is no consensus regarding the proper management of mediastinal ectopic or accessory thyroids, surgical excision must be considered because they can be malignant and can have mass effects on the surrounding structures. The surgical approach may vary between sternotomy and thoracotomy, but adequate exposure and access is a must as these are highly vascular masses and derive their vascularity directly from major vessels in the mediastinum. The above case is a rare presentation of primary ectopic goiter as myasthenia gravis, and it emphasizes that the possibility of ectopic or accessory goiter, although extremely rare, should also be considered in the differential diagnosis of mediastinal masses if imaging findings are not typical.
FEATURE ARTICLES
References 1. Gamblin TC, Jennings GR, Christie DB III, Thompson WM Jr, Dalton ML. Ectopic thyroid. Ann Thorac Surg 2003;75:1952–3. 2. Collins HD. III. Retrosternal accessory thyroid tumor: report of a case requiring removal, terminating fatally. Ann Surg 1905;41:661–6. 3. Vadasz P, Kotsis L. Surgical aspects of 175 mediastinal goiters. Eur J Cardiothorac Surg 1998;14:393–7. 4. De Assis JL, Scaff M, Zambon AA, Marchiori PE. Thyroid diseases and myasthenia gravis [in Portuguese]. Arq Neuropsiquiatr 1984;42:226–31. 5. Marin o M, Ricciardi R, Pinchera A, et al. Mild clinical expression of myasthenia gravis associated with autoimmune thyroid diseases. J Clin Endocrinol Metab 1997;82:438–43. 6. Finnie IA, Shields R, Sutton R, Donnelly R, Morris AI. Crohn’s disease and myasthenia gravis: a possible role for thymectomy. Gut 1994;35:278–9. 7. Foroozan R, Sambursky R. Ocular myasthenia gravis and inflammatory bowel disease: a case report and literature review. Br J Ophthalmol 2003;87:1186–7. 8. Spinner RJ, Moore KL, Gottfried MR, Lowe JE, Sabiston DC Jr. Thoracic intrathymic thyroid. Ann Surg 1994;220(1):91–6.
Minimally Invasive Tracheal Resection: Cervical Approach Plus Video-Assisted Thoracoscopic Surgery Sarah J. Lonie, MBBS (Hons), Stephanie Ch’ng, MS, Naveed Z. Alam, FRACS, and Gavin M. Wright, FRACS Department of Surgery, St. Vincent's Hospital, Melbourne; and Department of Surgical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
Tracheal resection for adenoid cystic carcinoma (ACC) is a well-documented procedure. Surgical resection of these lesions offers patients the greatest potential chance of survival. Midtracheal tumors are usually resected Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
Ann Thorac Surg 2015;100:2336–9
through a maximally invasive sternotomy or thoracotomy. We report a midtracheal resection of a symptomatic ACC in a 25-year-old man by video-assisted thoracoscopic hilar release and suprasternal anastomotic approaches. The patient’s recovery was complicated by chylothorax and pneumonia. (Ann Thorac Surg 2015;100:2336–9) Ó 2015 by The Society of Thoracic Surgeons
C
omplete surgical resection of adenoid cystic carcinoma (ACC) offers patients the greatest potential chance of survival and symptomatic relief [1–3]. The 5year survival after surgical resection of ACC is 60% to 100% compared with 10% from radiotherapy alone [4]. Resection of midtracheal tumors through maximally invasive sternotomy and thoracotomy surgical approaches is well documented [3, 4]. We report the first case of a hybrid technique for a minimally invasive midtracheal tumor resection combining video-assisted thorascopic surgery (VATS) for hilar release, followed by a cervical approach for tracheal resection. This was necessary because of the location and length of the tumor requiring resection (4-cm portion of trachea distal to the fifth tracheal ring). Simple excision and anastomosis without hilar release would have had a high risk of anastomotic breakdown. A 25-year-old man was referred to our emergency department for management of a midtracheal lesion causing almost complete obstruction of his airway. External computed tomography (CT) demonstrated a 95% obstructing lesion of the mid-upper trachea (Fig 1). He described a week’s history of hemoptysis and stridor in the setting of progressive dyspnea over the course of a year on a background of 10 years of chain smoking, and exposure to marijuana and asbestos. Emergency rigid bronchoscopy was performed, his airway was recanalized, and biopsy specimens were obtained (Fig 2). Histopathologic examination confirmed a diagnosis of ACC. Further workup included CT positron emission tomography, which demonstrated uptake in the tracheal region consistent with the area of the mass, and also in the right hip. The hip lesion was further investigated with magnetic resonance imaging (MRI), which suggested bursitis or hemangioma, less likely metastasis; for surveillance MRI follow-up. Tracheal resection and reconstruction were planned. The operation proceeded in two phases; first, a right VATS hilar release; second, resection of the tracheal mass with primary reconstruction through a cervical approach. Step 1 consisted of flexible bronchoscopy with confirmation of the tumor anatomy. Step 2 involved double-lumen intubation. Step 3 was a right VATS hilar release. The patient moved to the left lateral decubitus position. Three ports Accepted for publication Feb 18, 2015. Address correspondence to Dr Wright, 5th Flr, 55 Victoria Parade, Fitzroy 3065, Victoria, Australia; e-mail: [email protected].
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2015.02.099
Comment In this case, we report the use of the Hemolung RAS as a prolonged bridge to lung transplantation, and the first use of the Hemolung as a bridge to redo lung transplantation. Additionally, this is the first use of the device in a patient in the United States. A handful of case series have described the use of the Hemolung for up to 8 days in patients with chronic obstructive pulmonary disease, but reports describing its use in patients requiring respiratory support for other conditions are sparse [5, 6]. Although ECMO has served as an adequate support to bridge patients to lung transplantation, its use has been Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
2333
limited by the large cannulas and high circulating volumes required, inflammatory response in the presence of a large-area membrane oxygenator, and risks of bleeding and thrombolytic adverse events [1, 2]. The Hemolung offers an attractive and less invasive alternative for CO2 removal that can be implemented at the bedside. It could be used in some patients waiting for lung transplantation to reduce the risk of adverse events. Further study of the potential benefits of extracorporeal CO2 removal as an alternative to ECMO is both important and warranted, especially in patients who require mechanical support as a bridge to lung transplantation including redo cases. The authors wish to thank ALung Technologies for providing the Hemolung device and Shannon Wyszomierski for editorial support.
References 1. Bermudez CA, Rocha RV, Zaldonis D, et al. Extracorporeal membrane oxygenation as a bridge to lung transplant: midterm outcomes. Ann Thorac Surg 2011;92:1226–31; discussion 31–2. 2. Javidfar J, Bacchetta M. Bridge to lung transplantation with extracorporeal membrane oxygenation support. Curr Opin Organ Transplant 2012;17:496–502. 3. Kawut SM, Lederer DJ, Keshavjee S, et al. Outcomes after lung retransplantation in the modern era. Am J Respir Crit Care Med 2008;177:114–20. 4. Batchinsky AI, Jordan BS, Regn D, et al. Respiratory dialysis: reduction in dependence on mechanical ventilation by venovenous extracorporeal CO2 removal. Crit Care Med 2011;39: 1382–7. 5. Burki NK, Mani RK, Herth FJ, et al. A novel extracorporeal CO(2) removal system: results of a pilot study of hypercapnic respiratory failure in patients with COPD. Chest 2013;143: 678–86. 6. Bonin F, Sommerwerck U, Lund LW, Teschler H. Avoidance of intubation during acute exacerbation of chronic obstructive pulmonary disease for a lung transplant candidate using extracorporeal carbon dioxide removal with the Hemolung. J Thorac Cardiovasc Surg 2013;145:e43–4.
Primary Ectopic Mediastinal Goiter in a Patient With Crohn’s Disease Presenting as Myasthenia Gravis Sunil Kumar, MS, Mahesh Sultania, MS, Shivam Vatsal, MS, and M. C. Sharma, MD Department of Surgical Oncology, Dr BRA Institute Rotary Cancer Hospital, and Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
Mediastinum is an uncommon location for ectopic goiter. Primary ectopic mediastinal goiter has been reported to present mostly with compressive symptoms. We report a case of a 62-year-old man with history of Crohn’s disease, who presented with symptoms of myasthenia gravis and was found to have an anterior mediastinal mass. The 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2015.02.116
FEATURE ARTICLES
A 3,000-U initial bolus of heparin was administered for anticoagulation and then was titrated to maintain a partial thromoboplastin time of 45 to 60 seconds. Hemolung support was initiated at 470 to 540 mL/min flow and 500 rpm motor speed, which was slowly increased to 1,000 to 1,400 rpm (Fig 2). A notable decrease in systemic CO2 levels was observed within 24 hours, with progressive decreases over 4 to 6 days (Fig 3). During support, the patient received maintenance MV with decreased oxygen requirements to maintain arterial oxygen levels above 60 mm Hg (Fig 4). He was weaned from vasopressors, which were no longer required after 4 days of support. CO2 removal averaged 93 7 mL/min during days 2 through 20 of support. Systemic CO2 levels remained below 100 mm Hg (averaging 79 9 mm Hg on days 2–20) (Fig 3). After 9 days of support, the patient was accepted as a candidate for redo lung transplantation because of his considerable clinical improvement. He was awake, could be mobilized to sit on the edge of the bed, and maintained a better fluid balance with continuous venovenous hemodiafiltration. Donor lungs became available from a donor meeting the standard criteria 20 days after the initiation of Hemolung support. Standard preservation and surgical techniques were used for transplantation. The Hemolung device was removed at the time of the transplantation, and a double lung transplantation was performed with the use of cardiopulmonary support. After transplantation, the patient’s chest was left open for 3 days because of a size mismatch. The patient required MV for 7 days immediately after the transplantation. He remained in the ICU for 12 days. Hemolung support was not required at any point after transplantation. The patient required treatment for acute cellular rejection and was discharged 89 days after transplantation with adequate lung function, in good clinical condition, and ambulating independently. The patient did not encounter airway or other respiratory adverse events and is currently active and able to walk 1.5 to 2 miles without assistance. There was significant improvement in lung function from a forced expiratory volume in 1 second of 0.92 L before transplantation to 3.05 L 9 months after transplantation. The postoperative adverse event of renal failure requiring dialysis is still present; kidney transplantation is being considered.
CASE REPORT KUMAR ET AL ECTOPIC MEDIASTINAL GOITER WITH MYASTHENIA
2334
CASE REPORT KUMAR ET AL ECTOPIC MEDIASTINAL GOITER WITH MYASTHENIA
mass was resected completely with successful outcome. On histopathologic examination this mass turned out to be colloid goiter. This is an extremely rare presentation of a primary ectopic mediastinal goiter. (Ann Thorac Surg 2015;100:2333–6) Ó 2015 by The Society of Thoracic Surgeons
T
FEATURE ARTICLES
rue primary ectopic goiters are uncommon and account for less than 1% of all goiters [1]. They have been described at different sites from foramen caecum downward in the neck, but the mediastinum is a rare site for ectopic goiters. Among the various pathologic processes presenting as mediastinal masses, ectopic goiter is still considered as a diagnostic possibility. Most of the symptoms are because of compression on the surrounding structures. Here we report a case of primary mediastinal goiter in a patient with Crohn’s disease who presented with myasthenia gravis and was managed successfully with surgical resection of the mediastinal mass. To our knowledge there has been no report of a primary mediastinal goiter presenting as myasthenia gravis in the English literature. A 62-year-old male patient with a history of Crohn’s disease on medications for last 12 years was well until he exhibited generalized weakness, difficulty in swallowing, slurring of speech, and ptosis of the right eye, which appeared gradually over a period of 2 months. The patient was diagnosed to have myasthenia gravis (Osserman grade IV) with an acetylcholine receptor autoantibody titer of 13.46 nmol/L (positive if >0.4), and the edrophonium test was also positive. The patient was then started on pyridostigmine, and his dose of prednisolone was increased. His symptoms were deteriorating, and on further investigation his computed tomography scan of the chest showed the presence of an anterior mediastinal mass (Figs 1, 2) with a provisional diagnosis of thymoma. The thyroid function test and serum markers for germ cell tumor were within normal ranges. Because the myasthenic symptoms were not adequately managed by drugs, thymectomy was planned through a midline sternotomy approach. Intraoperatively a 13- 10-cm mass (Fig 3) was present in the anterior mediastinum with multiple vessels over its surface, in close contact with the superior vena cava and the trachea, which were pushed aside but were not invaded by the tumor. The tumor appeared to be arising from the thymic location. Complete excision of the mass was done with clearance of all the intervening connective tissue until reaching the lower border of the thyroid gland in the neck. The thyroid gland appeared normal and was totally separate from the mediastinal mass. The postoperative period was uneventful, and the patient was discharged on the eighth postoperative day.
Ann Thorac Surg 2015;100:2333–6
The histopathologic report of the tumor was surprising as it revealed no thymic tissue; rather, it showed only features of an adenomatous goiter (Fig 4). There was no lymphocytic infiltration, lymphoid follicle formation, or H€ urthle cell change. The patient had remarkable improvement in myasthenic symptoms; his drug requirements for myasthenia gravis have decreased to one fourth of the preoperative doses. During the follow-up period, ultrasound of the neck showed a normal thyroid, and the thyroid function has also been normal.
Comment Accessory thyroid is the presence of thyroid tissue other than the thyroid located anterolaterally between the second and fourth tracheal cartilages. The terms ectopic and accessory thyroid have been used interchangeably in the literature. Collins [2] defined true accessory thyroid as a distinct island of thyroid tissue separate from the typical thyroid body. Lingual thyroid is the most common form of thyroid ectopy, accounting for more than 90% of cases. Extralingual thyroid tissue is commonly located along the path of the thyroglossal duct but has also been reported in distant organs. Post-mortem studies suggest that asymptomatic thyroid tissue may be found in as many as 7% to 10% of adults. Ectopic thyroid tissue may coexist with a eutopic thyroid, as seen in our patient, or may be the only functioning tissue. The mediastinum is an unusual location for accessory thyroid tissue, and primary accessory mediastinal goiters are even more uncommon. They derive their blood supply completely from intrathoracic vessels. Vadasz and Kotsis [3] suggested that the origin of mediastinal goiter could be related to increased thyroid-stimulating hormone production after cervical thyroidectomy, although in this patient there
Accepted for publication Feb 6, 2015. Address correspondence to Dr Kumar, F-23, Ansari Nagar, AIIMS, New Delhi-110029, India; e-mail: [email protected].
Fig 1. Contrast-enhanced computed tomography scan of thorax showing the mediastinal mass in an axial section.
Ann Thorac Surg 2015;100:2333–6
CASE REPORT KUMAR ET AL ECTOPIC MEDIASTINAL GOITER WITH MYASTHENIA
2335
Fig 4. Photomicrograph of the tumor showing colloid goiter in low magnification (40) on H & E (Hematoxylin & Eosin) staining.
Fig 2. Contrast-enhanced computed tomography scan of thorax showing the mass in a coronal section.
was no such history and the baseline thyroid function was normal. Mediastinal goiter can remain asymptomatic until the structures located in the thoracic inlet are compressed. The most common symptoms are dyspnea, dysphagia, cough, hoarseness, and features of superior vena cava obstruction. This patient presented with features of
FEATURE ARTICLES
Fig 3. Macroscopic view of the excised specimen showing the lobulated solid mass.
myasthenia gravis, which was progressing even on drug therapy. We could not find any report of mediastinal goiter presenting as myasthenia in the literature, although there have been studies describing association of myasthenia with thyropathies, including nontoxic goiter, but all of them were in normally located cervical thyroid glands. There is no clinical correlation between myasthenia symptoms and thyroid dysfunction, nor a significant influence on myasthenic symptoms when the endocrine disorders improve [4]. Marin o and colleagues [5] suggested that acetylcholine receptor autoantibodies were more common in non–autoimmune thyroid disease than in autoimmune thyroid disease. Myasthenia gravis has been reported to be associated with both ulcerative colitis and Crohn’s disease, and is thought to be related to the presence of autoantibodies [6, 7]. This patient had a longstanding history of Crohn’s disease that was controlled with drugs, but the remarkable improvement in myasthenic symptoms after surgical resection of the mediastinal mass points toward a role of this mass in the disease pathology, making the existence of a random association less likely. Although the provisional preoperative diagnosis in this patient was thymoma, we could not find any thymic tissue in the resected specimen. Spinner and associates [8] described the entity called intrathymic thyroid, in which thyroid tissue was closely associated with atrophic thymic tissue, but none of the described patients presented with myasthenic symptoms. A possibility of autoantibody mechanism for the myasthenia may be present in this patient, as has been proposed about the association between myasthenia and non–autoimmune thyroid disorders. But it remains a hypothesis, and further immunopathologic studies will be required to understand this association. Thyroid scintigraphy is highly sensitive and specific for detecting normal and ectopic thyroid tissues. It should be done in cases when a mass is located in the superior mediastinum in continuity with the cervical thyroid, but it is generally not performed for masses that are lying in the
2336
CASE REPORT LONIE ET AL MINIMALLY INVASIVE TRACHEAL RESECTION
lower mediastinum because of a low index of suspicion, as was the scenario in this case. Based on the location, computed tomography–guided fine-needle aspiration or transbronchial needle aspiration can be used to obtain tissue diagnosis, but in almost all the reports the final diagnosis was made after surgical resection. Although there is no consensus regarding the proper management of mediastinal ectopic or accessory thyroids, surgical excision must be considered because they can be malignant and can have mass effects on the surrounding structures. The surgical approach may vary between sternotomy and thoracotomy, but adequate exposure and access is a must as these are highly vascular masses and derive their vascularity directly from major vessels in the mediastinum. The above case is a rare presentation of primary ectopic goiter as myasthenia gravis, and it emphasizes that the possibility of ectopic or accessory goiter, although extremely rare, should also be considered in the differential diagnosis of mediastinal masses if imaging findings are not typical.
FEATURE ARTICLES
References 1. Gamblin TC, Jennings GR, Christie DB III, Thompson WM Jr, Dalton ML. Ectopic thyroid. Ann Thorac Surg 2003;75:1952–3. 2. Collins HD. III. Retrosternal accessory thyroid tumor: report of a case requiring removal, terminating fatally. Ann Surg 1905;41:661–6. 3. Vadasz P, Kotsis L. Surgical aspects of 175 mediastinal goiters. Eur J Cardiothorac Surg 1998;14:393–7. 4. De Assis JL, Scaff M, Zambon AA, Marchiori PE. Thyroid diseases and myasthenia gravis [in Portuguese]. Arq Neuropsiquiatr 1984;42:226–31. 5. Marin o M, Ricciardi R, Pinchera A, et al. Mild clinical expression of myasthenia gravis associated with autoimmune thyroid diseases. J Clin Endocrinol Metab 1997;82:438–43. 6. Finnie IA, Shields R, Sutton R, Donnelly R, Morris AI. Crohn’s disease and myasthenia gravis: a possible role for thymectomy. Gut 1994;35:278–9. 7. Foroozan R, Sambursky R. Ocular myasthenia gravis and inflammatory bowel disease: a case report and literature review. Br J Ophthalmol 2003;87:1186–7. 8. Spinner RJ, Moore KL, Gottfried MR, Lowe JE, Sabiston DC Jr. Thoracic intrathymic thyroid. Ann Surg 1994;220(1):91–6.
Minimally Invasive Tracheal Resection: Cervical Approach Plus Video-Assisted Thoracoscopic Surgery Sarah J. Lonie, MBBS (Hons), Stephanie Ch’ng, MS, Naveed Z. Alam, FRACS, and Gavin M. Wright, FRACS Department of Surgery, St. Vincent's Hospital, Melbourne; and Department of Surgical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
Tracheal resection for adenoid cystic carcinoma (ACC) is a well-documented procedure. Surgical resection of these lesions offers patients the greatest potential chance of survival. Midtracheal tumors are usually resected Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
Ann Thorac Surg 2015;100:2336–9
through a maximally invasive sternotomy or thoracotomy. We report a midtracheal resection of a symptomatic ACC in a 25-year-old man by video-assisted thoracoscopic hilar release and suprasternal anastomotic approaches. The patient’s recovery was complicated by chylothorax and pneumonia. (Ann Thorac Surg 2015;100:2336–9) Ó 2015 by The Society of Thoracic Surgeons
C
omplete surgical resection of adenoid cystic carcinoma (ACC) offers patients the greatest potential chance of survival and symptomatic relief [1–3]. The 5year survival after surgical resection of ACC is 60% to 100% compared with 10% from radiotherapy alone [4]. Resection of midtracheal tumors through maximally invasive sternotomy and thoracotomy surgical approaches is well documented [3, 4]. We report the first case of a hybrid technique for a minimally invasive midtracheal tumor resection combining video-assisted thorascopic surgery (VATS) for hilar release, followed by a cervical approach for tracheal resection. This was necessary because of the location and length of the tumor requiring resection (4-cm portion of trachea distal to the fifth tracheal ring). Simple excision and anastomosis without hilar release would have had a high risk of anastomotic breakdown. A 25-year-old man was referred to our emergency department for management of a midtracheal lesion causing almost complete obstruction of his airway. External computed tomography (CT) demonstrated a 95% obstructing lesion of the mid-upper trachea (Fig 1). He described a week’s history of hemoptysis and stridor in the setting of progressive dyspnea over the course of a year on a background of 10 years of chain smoking, and exposure to marijuana and asbestos. Emergency rigid bronchoscopy was performed, his airway was recanalized, and biopsy specimens were obtained (Fig 2). Histopathologic examination confirmed a diagnosis of ACC. Further workup included CT positron emission tomography, which demonstrated uptake in the tracheal region consistent with the area of the mass, and also in the right hip. The hip lesion was further investigated with magnetic resonance imaging (MRI), which suggested bursitis or hemangioma, less likely metastasis; for surveillance MRI follow-up. Tracheal resection and reconstruction were planned. The operation proceeded in two phases; first, a right VATS hilar release; second, resection of the tracheal mass with primary reconstruction through a cervical approach. Step 1 consisted of flexible bronchoscopy with confirmation of the tumor anatomy. Step 2 involved double-lumen intubation. Step 3 was a right VATS hilar release. The patient moved to the left lateral decubitus position. Three ports Accepted for publication Feb 18, 2015. Address correspondence to Dr Wright, 5th Flr, 55 Victoria Parade, Fitzroy 3065, Victoria, Australia; e-mail: [email protected].
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2015.02.099
