Paraganglioma of the Posterior Mediastinum: Value of Magnetic Resonance Imaging Fumihiro Tanaka, MD, Morihisa Kitano, MD, Akitoshi Tatsumi, MD, Cheng-long Huang, MD, Miyuki Nagasawa, MD, Mari Mino, MD, Michimasa Matsuo, MD, and Kunio Ichijima, MD Departments of Thoracic Surgery, Respiratory Medicine, Magnetic Resonance, and Pathology, Tenri Hospital, Nara, Japan
A case of paraganglioma arising in the posterior mediastinum in a 29-year-old man diagnosed by magnetic resonance imaging is reported. Excision of mediastinal paraganglioma is often hazardous because of its rich vascular supply and tendency to involve surrounding structures.
P
araganglioma of the posterior mediastinum is a rare neurogenic tumor arising from the aorticosympathetic paraganglia [l].Because of the vascular nature of the tumor, angiography has been reported to be important for its diagnosis [2, 31. We wish to present a case in which magnetic resonance imaging (MRI) was used to determine both the vascular nature and the extent and relation of the tumor to surrounding structures. In July 1990, a 29-year-old man without symptoms was admitted to our hospital for evaluation of an abnormal density on a chest roentgenogram. On admission, blood pressure was 130/80 mm Hg and pulse rate was 70 beats per minute and regular. Results of other physical examination were normal. Laboratory studies including measurement of levels of urinary catecholamines, urinary vanillylmandelic acid, and urinary metanephrines showed normal results. Chest roentgenogram (Fig 1)and computed tomogram revealed a left posterior mediastinal mass at the level of the fifth, sixth, and seventh paravertebral sulci. Wholebody computed tomography revealed no other tumors. Magnetic resonance examination of the chest was performed. Axial T1-weighted images revealed a tumor with nonhomogeneous intermediate signal intensity with multiple signal-free areas suggesting signal void (Fig 2A); whereas, on axial T2-weighted images, it had high signal intensity (Fig 2B). The borders of the tumor were well defined. Magnetic resonance images showed no evidence of tumor invasion of adjacent structures (descending aorta, chest wall, and thoracic vertebrae) and no extension of intrathoracic tumor into the intraspinal space through intervertebral foramina (Figs 2A-C). Left thoracotomy was performed on August 21, 1990; arterial pressure and electrocardiogram were monitored continuously. A soft, circumscribed, extrapleural mass
Magnetic resonance imaging is valuable for the preoperative diagnosis of this vascular tumor as well as for determination of its resectability and appropriate surgical procedure. (Ann Thoruc Surg 1992;53:517-9)
was present in the costovertebral sulcus. The tumor was extremely vascular and firmly adherent to the adjacent vertebral column and fifth, sixth, and seventh ribs, but it did not invade these structures. During dissection, profuse hemorrhage occurred. The tumor was excised en bloc with an estimated blood loss of 1,500 mL. No remarkable changes in blood pressure or heart rate occurred during the operation. The excised tumor measured 6.5 X 5.0 X 3.0 cm and weighed 50 g. The cut surface was a reddish-tan color with areas of hemorrhage, and high vascularity was noted. Microscopic sections revealed that this tumor was composed of large cells with abundant eosinophilic granular cytoplasm and ovoid vesicular nuclei arranged in an alveolar pattern with a highly vascular intervening
Accepted for publication Aug 14, 1991 Address reprint requests to Dr Tanaka, Department of Thoracic Surgery, Tenri Hospital, 200 Mishima, Tenri, Nara, 632, Japan.
0 1992 by
The Society of Thoracic Surgeons
Fig 1 . Chest roentgenogram shows a left posterior mediastinal mass.
0003-4975/92/$5.00
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CASE REPORT TANAKA ET AL MEDIASTINAL PARAGANGLIOMA
A
Ann Thorac Surg 1992;53517-9
C
Fig 2. Magnetic resonance image of the chest shows a paravertebral mass with well-defined borders. (A) The axial T1-weighted (TR, 840 ms; TE, 15 ms) image shows a mass with nonhomogeneous intermediate signal intensity with multiple signal-free areas suggesting flow void (arrows). Flow void represents very fast blood pow in tumor vessels. ( B ) The axial T2-weighted (TR, 2,400 ms; TE, 70 ms) image shows a mass with high signal intensity with signal-free area. (C) Coronal TI W l (TR, 870 ms; TE, 15 ms) image demonstrates the mass does not invade vertebrae.
B
stroma. Grimelius staining demonstrated chromaffinpositive granules in the cytoplasm of tumor cells. The final diagnosis was paraganglioma of the posterior mediastinum.
Comment Glenner and Grimley [11 have classified the extraadrenal paraganglia into four groups on the basis of anatomic distribution, innervation, and microscopic structures: (1) branchiometric; (2) intravagal; (3) aorticosympathetic; and
(4)visceral-autonomic.Mediastinal paragangliomas occur most frequently in the middle compartment in association with the branchiometric paraganglia, and much less frequently in the posterior compartment in association with the aorticosympathetic paraganglia; only 40 cases of paraganglioma arising in the posterior mediastinum have been reported in the English-language literature. Excision of a posterior mediastinal paraganglioma is often difficult and hazardous because of the rich vascular supply and the tendency of the tumor to involve surrounding structures [2-51. Small [4] reported a case of
CASE REPORT TANAKA ET AL MEDIASTINAL PARAGANGLIOMA
Ann Thorac Surg
1992;53517-9
dumbbell-shapped paraganglioma in which intrathoracic tumor extended into the intraspinal space through the intervertebral foramen. Both laminectomy and thoracotomy were required in that case to achieve complete excision; however, profuse bleeding made it impossible to excise all of the tumor. Preoperative angiography to assess the vascularity and computed tomography to evaluate the extent of tumor have been reported to be valuable [2, 31. Magnetic resonance imaging is superior to computed tomography for evaluation of mediastinal tumors because the coronal and sagittal as well as axial magnetic resonance images enable determination of the overall tumor extent and the good contrast of soft tissues and vessels obtained with MRI enables easy distinction between tumor and great vessels [6].In addition, MRI may noninvasively and safely provide information about the vascularity of tumor as flow void, which represents very fast blood flow in its vessels, whereas angiography in case of paraganglioma is often hazardous because intraatrial injection of contrast medium may cause a severe cardiovascular crisis [3]. In this case, we used MRI to diagnose posterior mediastinal paraganglioma. The tumor was delineated as a nonhomogeneous mass with intermediate signal intensity on axial T1-weighted images and high signal intensity on axial T2-weighted images, as seen in other mediastinal tumors [6],and with flow void. Mediastinal tumors with high vascularity are limited to only four entities: Castleman’s disease, hemangioma, goiter, and paraganglioma [2].Hemangioma consists of a lake of slowly flowing blood, and does not produce intravascular signal void on MRI. Paraganglioma is one of the diagnoses of an intrathoracic paravertebral mass with flow void on MRI. In cases of intrathoracic paravertebral tumor, MRI should be performed not only to determine the extent of tumor but also to investigate the possibility of paraganglioma, because functional paraganglioma may produce cardiovascular complications during operation without
519
preoperative a- and Pblockade therapy. Even when the patient shows no symptoms of excessive catecholamine secretion before operation, manipulation of the tumor may induce hypertensive crisis, tachycardia, and cardiac arrhythmia [4]. Recently, iodine 131-metaiodobenzylguanidine has been proved to be very useful for localization of paraganglioma [7]. Because we were unable to use this new radiopharmaceutical technique, whole-body computed tomography was employed to detect possible multiple paragangliomas. In conclusion, MRI is most useful for diagnosing and evaluating the extent of paraganglioma of the posterior mediastinum, and in planning the complete excision of the tumor.
References 1. Glenner GG, Grimley PM. Tumor of the extra-adrenal paraganglion system (including chemoreceptors).In: Firminger HI, ed. Atlas of tumor pathology, 2nd series, fascicle 9. Washington, D C Armed Forces Institute of Pathology, 1974134. 2. Drucker EA, McLoud TC, Dedrick CG, Hilgenberg AD, Geller SC, Shepard JO. Mediastinal paraganglioma:radiologic evaluation of an unusual vascular tumor. AJR 1987;148:521-2. 3. Hodgkinson DJ, Telander RL, Sheps SG, Gilchrist GS, Crowe JK. Extra-adrenal intrathoracic functioning paraganglioma (pheochromocytoma) in childhood. Mayo Clin Proc 1980;55: 271-6. 4. Small P. A case of non-chromaffin paraganglioma presenting in pregnancy as a dumb-bell tumor. Br J Radio1 1972;45:219-23. 5. Evora PRB, Bongiovani HL, Sgarbieri RN, et al. Nonfunctioning paraganglioma of the posterior mediastinum. Scand J Thorac Cardiovasc Surg 1988;22:295-7. 6. Higgins CB. The thorax. In: Higgins CB, Hricak HH, eds. Magnetic resonance imaging of the body. New York: Raven Press, 198711. 7. Sheps SG, Brown ML. Localization of mediastinal paragangliomas (pheochromocytoma).Chest 1985;87807-9.
A case of paraganglioma arising in the posterior mediastinum in a 29-year-old man diagnosed by magnetic resonance imaging is reported. Excision of mediastinal paraganglioma is often hazardous because of its rich vascular supply and tendency to involve surrounding structures.
P
araganglioma of the posterior mediastinum is a rare neurogenic tumor arising from the aorticosympathetic paraganglia [l].Because of the vascular nature of the tumor, angiography has been reported to be important for its diagnosis [2, 31. We wish to present a case in which magnetic resonance imaging (MRI) was used to determine both the vascular nature and the extent and relation of the tumor to surrounding structures. In July 1990, a 29-year-old man without symptoms was admitted to our hospital for evaluation of an abnormal density on a chest roentgenogram. On admission, blood pressure was 130/80 mm Hg and pulse rate was 70 beats per minute and regular. Results of other physical examination were normal. Laboratory studies including measurement of levels of urinary catecholamines, urinary vanillylmandelic acid, and urinary metanephrines showed normal results. Chest roentgenogram (Fig 1)and computed tomogram revealed a left posterior mediastinal mass at the level of the fifth, sixth, and seventh paravertebral sulci. Wholebody computed tomography revealed no other tumors. Magnetic resonance examination of the chest was performed. Axial T1-weighted images revealed a tumor with nonhomogeneous intermediate signal intensity with multiple signal-free areas suggesting signal void (Fig 2A); whereas, on axial T2-weighted images, it had high signal intensity (Fig 2B). The borders of the tumor were well defined. Magnetic resonance images showed no evidence of tumor invasion of adjacent structures (descending aorta, chest wall, and thoracic vertebrae) and no extension of intrathoracic tumor into the intraspinal space through intervertebral foramina (Figs 2A-C). Left thoracotomy was performed on August 21, 1990; arterial pressure and electrocardiogram were monitored continuously. A soft, circumscribed, extrapleural mass
Magnetic resonance imaging is valuable for the preoperative diagnosis of this vascular tumor as well as for determination of its resectability and appropriate surgical procedure. (Ann Thoruc Surg 1992;53:517-9)
was present in the costovertebral sulcus. The tumor was extremely vascular and firmly adherent to the adjacent vertebral column and fifth, sixth, and seventh ribs, but it did not invade these structures. During dissection, profuse hemorrhage occurred. The tumor was excised en bloc with an estimated blood loss of 1,500 mL. No remarkable changes in blood pressure or heart rate occurred during the operation. The excised tumor measured 6.5 X 5.0 X 3.0 cm and weighed 50 g. The cut surface was a reddish-tan color with areas of hemorrhage, and high vascularity was noted. Microscopic sections revealed that this tumor was composed of large cells with abundant eosinophilic granular cytoplasm and ovoid vesicular nuclei arranged in an alveolar pattern with a highly vascular intervening
Accepted for publication Aug 14, 1991 Address reprint requests to Dr Tanaka, Department of Thoracic Surgery, Tenri Hospital, 200 Mishima, Tenri, Nara, 632, Japan.
0 1992 by
The Society of Thoracic Surgeons
Fig 1 . Chest roentgenogram shows a left posterior mediastinal mass.
0003-4975/92/$5.00
518
CASE REPORT TANAKA ET AL MEDIASTINAL PARAGANGLIOMA
A
Ann Thorac Surg 1992;53517-9
C
Fig 2. Magnetic resonance image of the chest shows a paravertebral mass with well-defined borders. (A) The axial T1-weighted (TR, 840 ms; TE, 15 ms) image shows a mass with nonhomogeneous intermediate signal intensity with multiple signal-free areas suggesting flow void (arrows). Flow void represents very fast blood pow in tumor vessels. ( B ) The axial T2-weighted (TR, 2,400 ms; TE, 70 ms) image shows a mass with high signal intensity with signal-free area. (C) Coronal TI W l (TR, 870 ms; TE, 15 ms) image demonstrates the mass does not invade vertebrae.
B
stroma. Grimelius staining demonstrated chromaffinpositive granules in the cytoplasm of tumor cells. The final diagnosis was paraganglioma of the posterior mediastinum.
Comment Glenner and Grimley [11 have classified the extraadrenal paraganglia into four groups on the basis of anatomic distribution, innervation, and microscopic structures: (1) branchiometric; (2) intravagal; (3) aorticosympathetic; and
(4)visceral-autonomic.Mediastinal paragangliomas occur most frequently in the middle compartment in association with the branchiometric paraganglia, and much less frequently in the posterior compartment in association with the aorticosympathetic paraganglia; only 40 cases of paraganglioma arising in the posterior mediastinum have been reported in the English-language literature. Excision of a posterior mediastinal paraganglioma is often difficult and hazardous because of the rich vascular supply and the tendency of the tumor to involve surrounding structures [2-51. Small [4] reported a case of
CASE REPORT TANAKA ET AL MEDIASTINAL PARAGANGLIOMA
Ann Thorac Surg
1992;53517-9
dumbbell-shapped paraganglioma in which intrathoracic tumor extended into the intraspinal space through the intervertebral foramen. Both laminectomy and thoracotomy were required in that case to achieve complete excision; however, profuse bleeding made it impossible to excise all of the tumor. Preoperative angiography to assess the vascularity and computed tomography to evaluate the extent of tumor have been reported to be valuable [2, 31. Magnetic resonance imaging is superior to computed tomography for evaluation of mediastinal tumors because the coronal and sagittal as well as axial magnetic resonance images enable determination of the overall tumor extent and the good contrast of soft tissues and vessels obtained with MRI enables easy distinction between tumor and great vessels [6].In addition, MRI may noninvasively and safely provide information about the vascularity of tumor as flow void, which represents very fast blood flow in its vessels, whereas angiography in case of paraganglioma is often hazardous because intraatrial injection of contrast medium may cause a severe cardiovascular crisis [3]. In this case, we used MRI to diagnose posterior mediastinal paraganglioma. The tumor was delineated as a nonhomogeneous mass with intermediate signal intensity on axial T1-weighted images and high signal intensity on axial T2-weighted images, as seen in other mediastinal tumors [6],and with flow void. Mediastinal tumors with high vascularity are limited to only four entities: Castleman’s disease, hemangioma, goiter, and paraganglioma [2].Hemangioma consists of a lake of slowly flowing blood, and does not produce intravascular signal void on MRI. Paraganglioma is one of the diagnoses of an intrathoracic paravertebral mass with flow void on MRI. In cases of intrathoracic paravertebral tumor, MRI should be performed not only to determine the extent of tumor but also to investigate the possibility of paraganglioma, because functional paraganglioma may produce cardiovascular complications during operation without
519
preoperative a- and Pblockade therapy. Even when the patient shows no symptoms of excessive catecholamine secretion before operation, manipulation of the tumor may induce hypertensive crisis, tachycardia, and cardiac arrhythmia [4]. Recently, iodine 131-metaiodobenzylguanidine has been proved to be very useful for localization of paraganglioma [7]. Because we were unable to use this new radiopharmaceutical technique, whole-body computed tomography was employed to detect possible multiple paragangliomas. In conclusion, MRI is most useful for diagnosing and evaluating the extent of paraganglioma of the posterior mediastinum, and in planning the complete excision of the tumor.
References 1. Glenner GG, Grimley PM. Tumor of the extra-adrenal paraganglion system (including chemoreceptors).In: Firminger HI, ed. Atlas of tumor pathology, 2nd series, fascicle 9. Washington, D C Armed Forces Institute of Pathology, 1974134. 2. Drucker EA, McLoud TC, Dedrick CG, Hilgenberg AD, Geller SC, Shepard JO. Mediastinal paraganglioma:radiologic evaluation of an unusual vascular tumor. AJR 1987;148:521-2. 3. Hodgkinson DJ, Telander RL, Sheps SG, Gilchrist GS, Crowe JK. Extra-adrenal intrathoracic functioning paraganglioma (pheochromocytoma) in childhood. Mayo Clin Proc 1980;55: 271-6. 4. Small P. A case of non-chromaffin paraganglioma presenting in pregnancy as a dumb-bell tumor. Br J Radio1 1972;45:219-23. 5. Evora PRB, Bongiovani HL, Sgarbieri RN, et al. Nonfunctioning paraganglioma of the posterior mediastinum. Scand J Thorac Cardiovasc Surg 1988;22:295-7. 6. Higgins CB. The thorax. In: Higgins CB, Hricak HH, eds. Magnetic resonance imaging of the body. New York: Raven Press, 198711. 7. Sheps SG, Brown ML. Localization of mediastinal paragangliomas (pheochromocytoma).Chest 1985;87807-9.
