Parathyroid adenoma with cervical tracheal compression ROBERT H. WOODS, MD, and DAVID W. EISELE, MD, Baltimore, Maryland
Extrinsic tracheal compression is most commonly caused by thyroid masses, vascular anomalies, esophageal abnormalities, and various other paratracheal masses. Because of their rare location in the retrotracheal area, parathyroid adenomas of significant size may cause tracheal compression. Flow-volume loop studies can be of great diagnostic value in the evaluation of the location and degree of tracheal obstruction. We present the unusual case of a patient with symptomatic, extrinsic compression of the cervical trachea caused by
a large parathyroid adenoma. The patient's history, evaluation-including flow-volume loop studies, and treatment are reported. CASE REPORT
A 38-year-old woman with a history of postpartum hypothyroidism, obesity, and hypertension was evaluated for a chronic dry cough that developed approximately one half year after being placed on captopril for hypertension control. The captopril was discontinued, but her cough persisted. In addition, she noted a constant irritation in her throat and mild hoarseness. She had no dyspnea on exertion, stridor, wheezing, hemotysis, or dysphagia. Physical examination revealed an obese woman in no acute distress. Indirect laryngoscopy showed very mild true vocal cord edema bilaterally, but normal symmetrical motion and no lesions. A 1.5 em mobile neck mass was palpated inferolateral to the level of the cricoid on the right. The thyroid was small, normal to palpation, and distinct from the mass. There were no other palpable neck masses. There was no detectable stridor or wheezing by auscultation. The remainder of the physical examination was normal.
From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins Medical Institutions. Presented at the Annual Meeting of the American Academy of Otolaryngology-Head and Neck Surgery, Kansas City, Mo., Sept. 2226, 1991. Received for publication Sept. 25, 1991; revision received March 24, 1992; accepted March 30, 1992. Reprint requests: David W. Eisele, MD, Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins Hospital, P. O. Box 41402, Baltimore, MD 21203-6402.
23/4/38636
FLOW-VOLUME LOOP PREOPERATIVE -
POSTOPERATIVE - - -
6 ElIplration
4
--
2 FLOW 0 II-----r--+-~-~~-r--~ LIS 4 5 -2 Inspirotion -4
---
•
---
~~
MID VITAL CAPACITY
VOLUME (L) Fig.1. Preoperative and postoperative flow-volume loop studies. Note postoperative improvement in inspiratory and expiratory flow rates at mid vital capacity (arrow).
463
OlolaryngologyHead and Neck Surgery
464 Case Reports
Fig. 3. Surgical specimen (large parathyroid adenoma).
Fig. 2. Small portion of parathyroid adenoma [clomp tip) visible in tracheoesophageal groove medial to carotid artery [e). Thyroid lobe is retracted medially. The majority of the adenoma is retrotracheal.
Radiographs and CT scan of the chest were norma!. Pulmonary function tests with flow-volume loop study demonstrated a reduction in inspiratory flow and expiratory flow consistent with a fixed tracheal obstruction (Fig. I). Fiberoptic bronchoscopy was performed and revealed right posterolateral extrinsic compression of the trachea approximately 2 to 3 em below the glottis. This mass was nonpulsatile and noncompressible. Laboratory evaluation was normal, with the exception of a persistently elevated serum calcium of 12.0 (8.5 to 10.6) dLi m!. Cvterminal parathyroid hormone levels were also elevated on two occasions to 490 pg/ml (0 to 340 pg/ml) and 800 pg/ml (0 to 340 pg/ml). Thyroid function tests were normal. Ultrasound examination of the neck demonstrated a 2.7 em x 1.2 em x 1.3 em mass, medial and posterior to the right carotid artery, just below the level of the cricoid cartilage. A thallium-technetium-99m-pertechnetate subtraction scan revealed increased thallium uptake diffusely in the region of the right thyroid lobe and persistent increased thallium uptake on the thallium minus technetium image, suggestive of a right parathyroid adenoma. The tcchnetium-v'L-pertcchnotate scan revealed the thyroid gland to be nonna!.
Exploration of the neck revealed a beefy red parathyroid adenoma posterior to the right thyroid lobe, between common carotid artery and the trachea, extending into the tracheoesophageal groove (Fig. 2). The adenoma measured 2.7 em x 1.7 em x 1.4 em and weighed 3.12 grams (Fig. 3). A normal ipsilateral inferior parathyroid gland was identified and a biopsy of this gland revealed normal parathyroid tissue. Normal superior and inferior parathyroid glands were found in the contralateral neck. The thyroid was normal to palpation. Histologic examination of the adenoma showed sheets of parathyroid chief cells with no interspersed stromal fat. There was an intact and smooth fibrous capsule. No rim of normal parathyroid tissue was seen. Postoperatively, transient hypocalcemia developed, for which the woman received calcium replacement. She had an otherwise uneventful postoperative course. One month later, her calcium and parathyroid hormone levels had returned to normal. Her chronic cough and throat irritation resolved. A repeat flow-volume loop I year postoperatively was normal (Fig. I).
DISCUSSION
Extrinsic compressive narrowing of the trachea is usually caused by thyroid masses such as adenomas, cysts, goiters, or malignancies. The rare problem of spontaneous hemorrhage into a parathyroid adenoma might cause acute tracheal compression, depending on the location of the adenoma and the degree of hemorrhage. I The case reported represents a very unusual cause of chronic cervical tracheal compression, a large parathyroid adenoma. A thorough review of the literature failed to identify a similar presentation. Local symptoms related to a parathyroid adenoma are uncommon. Most adenomas are relatively small in
Volume 107 Number 3 September 1992
size when removed, although massive parathyroid adenomas weighing more than 100 grams can occur. 2 Even an enlarged parathyroid adenoma would not be expected to cause cervical tracheal compression in its usual anatomic locations. The superior parathyroid is usually located in the cricothyroid and juxtacricoid region or on the posterior aspect of the upper pole of the thyroid." The inferior parathyroid is most commonly located on posterior, inferior aspect of the thyroid lobe. 3 Aberrant locations of the parathyroids occur in 15% to 20% of cases and, in rare instances, are retropharyngeal, retroesophageal, or retrotracheal. 4 The shape of the adenoma is influenced by its location. 5 In the case presented, the adenoma was found deep in the neck, between the common carotid artery and trachea, deep to the upper pole of the thyroid. It was ovoid in shape, perhaps as a result of its juxtaposition to the membranous trachea allowing its symmetric growth. The adenoma in this location resulted in extrinsic tracheal compression, which was observed endoscopically. The mass effect of the adenoma could have been a source of irritation to the trachea, contributing to the patient's chronic cough and throat discomfort. The clinical presentation of chronic tracheal obstruction varies depending upon the etiology. Progressive dyspnea is the usual presenting complaint. This is often first noticed with exertion. Other symptoms include a nonproductive cough-as in our patient, stridor, wheezing, hemoptysis, cyanosis, or change in voice quality and volume." The case presented is unusual in that the patient's unexplained and persistent cough and respiratory symptoms were the presenting symptoms that resulted in the diagnosis of hyperparathyroidism. The woman had no other symptoms or complications of hypercalcemia. Flow-volume loop studies are useful for the evaluation of tracheal obstruction and can help to determine the site and degree of tracheal obstruction. Of major importance when examining the flow-volume loop is distinguishing between fixed and variable obstructions. Because of transmural pressure differences, the intrathoracic trachea tends to collapse during forced expiration and dilate during forced inspiration. The extrathoracic trachea behaves in the exact opposite manner. With variable extrathoracic obstructions, such as bilateral vocal cord paralysis, the trachea collapses during
Case Reports
465
inspiration, but not during expiration, creating a plateau soley on the inspiratory loop. Variable intrathoracic lesions-such as crescentic tracheal tumors, on the other hand-restrict expiration to a greater degree than inspiration, creating a plateau in the expiratory limb of the loop, with a relatively normal inspiratory loop. Fixed obstructions are unaffected by these transmural forces. A fixed obstruction such as tracheal stenosis, for example, will produce a flow-volume loop with blunted peak inspiratory and expiratory flow rates. 6 In our patient, the flow-volume loop was blunted both during peak inspiration and expiration, thus suggesting a fixed obstructive lesion. Removal of the adenoma resulted in improved peak inspiratory and expiratory flow rates on the flow-volume loop study, objectively confirming the presence and degree of tracheal obstruction by the parathyroid adenoma. 0S
CONCLUSION
An unusual case of a parathyroid adenoma causing symptomatic cervical tracheal extrinsic compression is reported. Objective documentation of the degree and resolution of airway obstruction after removal of the adenoma by preoperative and postoperative flow-volume loop studies is presented. REFERENCES I. Hotes LS, Barzilay J. Cloud LP, Rolla AR. Case report: spon-
2. 3. 4. 5.
6.
7.
8.
taneous hematoma of a parathyroid adenoma. Am J Med Sci 1989;297:331-3. Schwartz MR. Pathology of the thyroid and parathyroid glands. Otolaryngol Clin North Am 1990;23:175-215. Wang CA. The anatomic basis of parathyroid surgery. Ann Surg 1976;183:271-5. Petti GH, Jr. Hyperparathyroidism. Otolaryngol Clin North Am 1990;23:339-55. Wang CA. Surgical management of parathyroid disorders. In: Cummings CW, et a\., eds. Otolaryngology-head and neck surgery. St. Louis: CV Mosby Co., 1986:2525-42. Fraser RG, Pare PJA, Pare PD. Fraser RS, Genereux GP. Diagnosis of diseases of the chest. 3rd ed. Philadelphia: WB Saunders Co., 1990:1975-2006. Miller RD. Obstructing lesions of the larynx and trachea: clinical and pathophysiological aspects. In: Fishman AP, ed. Pulmonary diseases and disorders. 2nd ed. New York: McGraw-Hill, Inc., 1988:1173-87. Welch MH. Ventilatory functions of the lungs. In: Guenter CA. Welch MH, eds. Pulmonary medicine. 2nd ed. Philadelphia: JB Lippincott Co., 1982:123-9.
Extrinsic tracheal compression is most commonly caused by thyroid masses, vascular anomalies, esophageal abnormalities, and various other paratracheal masses. Because of their rare location in the retrotracheal area, parathyroid adenomas of significant size may cause tracheal compression. Flow-volume loop studies can be of great diagnostic value in the evaluation of the location and degree of tracheal obstruction. We present the unusual case of a patient with symptomatic, extrinsic compression of the cervical trachea caused by
a large parathyroid adenoma. The patient's history, evaluation-including flow-volume loop studies, and treatment are reported. CASE REPORT
A 38-year-old woman with a history of postpartum hypothyroidism, obesity, and hypertension was evaluated for a chronic dry cough that developed approximately one half year after being placed on captopril for hypertension control. The captopril was discontinued, but her cough persisted. In addition, she noted a constant irritation in her throat and mild hoarseness. She had no dyspnea on exertion, stridor, wheezing, hemotysis, or dysphagia. Physical examination revealed an obese woman in no acute distress. Indirect laryngoscopy showed very mild true vocal cord edema bilaterally, but normal symmetrical motion and no lesions. A 1.5 em mobile neck mass was palpated inferolateral to the level of the cricoid on the right. The thyroid was small, normal to palpation, and distinct from the mass. There were no other palpable neck masses. There was no detectable stridor or wheezing by auscultation. The remainder of the physical examination was normal.
From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins Medical Institutions. Presented at the Annual Meeting of the American Academy of Otolaryngology-Head and Neck Surgery, Kansas City, Mo., Sept. 2226, 1991. Received for publication Sept. 25, 1991; revision received March 24, 1992; accepted March 30, 1992. Reprint requests: David W. Eisele, MD, Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins Hospital, P. O. Box 41402, Baltimore, MD 21203-6402.
23/4/38636
FLOW-VOLUME LOOP PREOPERATIVE -
POSTOPERATIVE - - -
6 ElIplration
4
--
2 FLOW 0 II-----r--+-~-~~-r--~ LIS 4 5 -2 Inspirotion -4
---
•
---
~~
MID VITAL CAPACITY
VOLUME (L) Fig.1. Preoperative and postoperative flow-volume loop studies. Note postoperative improvement in inspiratory and expiratory flow rates at mid vital capacity (arrow).
463
OlolaryngologyHead and Neck Surgery
464 Case Reports
Fig. 3. Surgical specimen (large parathyroid adenoma).
Fig. 2. Small portion of parathyroid adenoma [clomp tip) visible in tracheoesophageal groove medial to carotid artery [e). Thyroid lobe is retracted medially. The majority of the adenoma is retrotracheal.
Radiographs and CT scan of the chest were norma!. Pulmonary function tests with flow-volume loop study demonstrated a reduction in inspiratory flow and expiratory flow consistent with a fixed tracheal obstruction (Fig. I). Fiberoptic bronchoscopy was performed and revealed right posterolateral extrinsic compression of the trachea approximately 2 to 3 em below the glottis. This mass was nonpulsatile and noncompressible. Laboratory evaluation was normal, with the exception of a persistently elevated serum calcium of 12.0 (8.5 to 10.6) dLi m!. Cvterminal parathyroid hormone levels were also elevated on two occasions to 490 pg/ml (0 to 340 pg/ml) and 800 pg/ml (0 to 340 pg/ml). Thyroid function tests were normal. Ultrasound examination of the neck demonstrated a 2.7 em x 1.2 em x 1.3 em mass, medial and posterior to the right carotid artery, just below the level of the cricoid cartilage. A thallium-technetium-99m-pertechnetate subtraction scan revealed increased thallium uptake diffusely in the region of the right thyroid lobe and persistent increased thallium uptake on the thallium minus technetium image, suggestive of a right parathyroid adenoma. The tcchnetium-v'L-pertcchnotate scan revealed the thyroid gland to be nonna!.
Exploration of the neck revealed a beefy red parathyroid adenoma posterior to the right thyroid lobe, between common carotid artery and the trachea, extending into the tracheoesophageal groove (Fig. 2). The adenoma measured 2.7 em x 1.7 em x 1.4 em and weighed 3.12 grams (Fig. 3). A normal ipsilateral inferior parathyroid gland was identified and a biopsy of this gland revealed normal parathyroid tissue. Normal superior and inferior parathyroid glands were found in the contralateral neck. The thyroid was normal to palpation. Histologic examination of the adenoma showed sheets of parathyroid chief cells with no interspersed stromal fat. There was an intact and smooth fibrous capsule. No rim of normal parathyroid tissue was seen. Postoperatively, transient hypocalcemia developed, for which the woman received calcium replacement. She had an otherwise uneventful postoperative course. One month later, her calcium and parathyroid hormone levels had returned to normal. Her chronic cough and throat irritation resolved. A repeat flow-volume loop I year postoperatively was normal (Fig. I).
DISCUSSION
Extrinsic compressive narrowing of the trachea is usually caused by thyroid masses such as adenomas, cysts, goiters, or malignancies. The rare problem of spontaneous hemorrhage into a parathyroid adenoma might cause acute tracheal compression, depending on the location of the adenoma and the degree of hemorrhage. I The case reported represents a very unusual cause of chronic cervical tracheal compression, a large parathyroid adenoma. A thorough review of the literature failed to identify a similar presentation. Local symptoms related to a parathyroid adenoma are uncommon. Most adenomas are relatively small in
Volume 107 Number 3 September 1992
size when removed, although massive parathyroid adenomas weighing more than 100 grams can occur. 2 Even an enlarged parathyroid adenoma would not be expected to cause cervical tracheal compression in its usual anatomic locations. The superior parathyroid is usually located in the cricothyroid and juxtacricoid region or on the posterior aspect of the upper pole of the thyroid." The inferior parathyroid is most commonly located on posterior, inferior aspect of the thyroid lobe. 3 Aberrant locations of the parathyroids occur in 15% to 20% of cases and, in rare instances, are retropharyngeal, retroesophageal, or retrotracheal. 4 The shape of the adenoma is influenced by its location. 5 In the case presented, the adenoma was found deep in the neck, between the common carotid artery and trachea, deep to the upper pole of the thyroid. It was ovoid in shape, perhaps as a result of its juxtaposition to the membranous trachea allowing its symmetric growth. The adenoma in this location resulted in extrinsic tracheal compression, which was observed endoscopically. The mass effect of the adenoma could have been a source of irritation to the trachea, contributing to the patient's chronic cough and throat discomfort. The clinical presentation of chronic tracheal obstruction varies depending upon the etiology. Progressive dyspnea is the usual presenting complaint. This is often first noticed with exertion. Other symptoms include a nonproductive cough-as in our patient, stridor, wheezing, hemoptysis, cyanosis, or change in voice quality and volume." The case presented is unusual in that the patient's unexplained and persistent cough and respiratory symptoms were the presenting symptoms that resulted in the diagnosis of hyperparathyroidism. The woman had no other symptoms or complications of hypercalcemia. Flow-volume loop studies are useful for the evaluation of tracheal obstruction and can help to determine the site and degree of tracheal obstruction. Of major importance when examining the flow-volume loop is distinguishing between fixed and variable obstructions. Because of transmural pressure differences, the intrathoracic trachea tends to collapse during forced expiration and dilate during forced inspiration. The extrathoracic trachea behaves in the exact opposite manner. With variable extrathoracic obstructions, such as bilateral vocal cord paralysis, the trachea collapses during
Case Reports
465
inspiration, but not during expiration, creating a plateau soley on the inspiratory loop. Variable intrathoracic lesions-such as crescentic tracheal tumors, on the other hand-restrict expiration to a greater degree than inspiration, creating a plateau in the expiratory limb of the loop, with a relatively normal inspiratory loop. Fixed obstructions are unaffected by these transmural forces. A fixed obstruction such as tracheal stenosis, for example, will produce a flow-volume loop with blunted peak inspiratory and expiratory flow rates. 6 In our patient, the flow-volume loop was blunted both during peak inspiration and expiration, thus suggesting a fixed obstructive lesion. Removal of the adenoma resulted in improved peak inspiratory and expiratory flow rates on the flow-volume loop study, objectively confirming the presence and degree of tracheal obstruction by the parathyroid adenoma. 0S
CONCLUSION
An unusual case of a parathyroid adenoma causing symptomatic cervical tracheal extrinsic compression is reported. Objective documentation of the degree and resolution of airway obstruction after removal of the adenoma by preoperative and postoperative flow-volume loop studies is presented. REFERENCES I. Hotes LS, Barzilay J. Cloud LP, Rolla AR. Case report: spon-
2. 3. 4. 5.
6.
7.
8.
taneous hematoma of a parathyroid adenoma. Am J Med Sci 1989;297:331-3. Schwartz MR. Pathology of the thyroid and parathyroid glands. Otolaryngol Clin North Am 1990;23:175-215. Wang CA. The anatomic basis of parathyroid surgery. Ann Surg 1976;183:271-5. Petti GH, Jr. Hyperparathyroidism. Otolaryngol Clin North Am 1990;23:339-55. Wang CA. Surgical management of parathyroid disorders. In: Cummings CW, et a\., eds. Otolaryngology-head and neck surgery. St. Louis: CV Mosby Co., 1986:2525-42. Fraser RG, Pare PJA, Pare PD. Fraser RS, Genereux GP. Diagnosis of diseases of the chest. 3rd ed. Philadelphia: WB Saunders Co., 1990:1975-2006. Miller RD. Obstructing lesions of the larynx and trachea: clinical and pathophysiological aspects. In: Fishman AP, ed. Pulmonary diseases and disorders. 2nd ed. New York: McGraw-Hill, Inc., 1988:1173-87. Welch MH. Ventilatory functions of the lungs. In: Guenter CA. Welch MH, eds. Pulmonary medicine. 2nd ed. Philadelphia: JB Lippincott Co., 1982:123-9.
