Upload
others
View
6
Download
0
Embed Size (px)
Citation preview
Robert 1. Sataloff
CARE OF THE PROFESSIONAL VOICE Robert I. Sataloff, MD, DMA, Associate Editor
I,)Ut fldl 01 Singing, SOOCIObLI 1)ecLInbet 2(11
Volunic 64, No. 2, pp. 195-198 Copyright 16 2007 National Association of Teachers of Singing
INTRODUCTION
T
hyroid cancer is relatively common. It accounts for 1% to
1.5% of all new cases of cancer in the United States,' amount-
ing to between 13,000 and 20,000 new cases of thyroid can-
cer annually. About 1,100 to 1,300 deaths result from thy-
roid cancer each year in the United States. 2 Normal thyroid hormone
levels are important to laryngeal function, so thyroid damage even
from medical cancer treatment can cause voice problems in singers.
In addition, the thyroid gland lies in close proximity to the larynx and
the nerves that move the vocal folds. Vocal fold paresis (weakness) or
paralysis are fairly common complications of thyroid surgery. It is help-
ful for singing teachers to have a basic familiarity with the nature, eval-uation, and treatment of thyroid cancer.
ANATOMY
The thyroid gland is located below the strap muscles of the neck, in front
of the second and third tracheal rings, and just below the cricoid car-
tilage of the larynx. The right and left lobes of the thyroid gland are con-
nected by a narrow band called the isthmus. Berry ligaments suspend
the thyroid gland to the larynx and trachea. The recurrent laryngeal
nerves, which innervate all of the laryngeal muscles except the cricothy-
roid muscles, course through the tracheo-esophageal groove deep to
the thyroid gland. They run close to the inferior thyroid arteries and
Berry ligaments which must be operated upon during thyroidectomy.
The superior laryngeal nerves also run in close approximation to the
upper portions of the thyroid gland and the superior thyroid arteries.
CLINICAL PRESENTATION
Typically, thyroid cancers present as masses or "nodules" in the thy-
roid gland. However, most nodules are not cancer. Palpable thyroid
nodules (bumps that can be felt in the neck) are present in 4% to 7%
of adults in the United States.' When cadavers are dissected, nodules
that were not palpable are found in between 37% and 57% of thyroid
glands.' Only about 5% of thyroid nodules are cancerous in adults.'
However, in patients under twenty years of age, 20% to 50% of thy-roid nodules are malignant. 6 In adults, nodules in males are cancer-
Thyroid Cancer Robert Thayer Sataloff
Novi-mm-OM : ( 2007 195
Robert T Sata1off, MD, DMA
ous approximately twice as frequently as they are in fe-males.
When thyroid neoplasms cause hoarseness, localized
neck pain, difficulty breathing or swallowing, or other
such symptoms that are uncommon for benign nodules,
malignancy is suspected readily. However, many thy-
roid cancers present simply as painless, enlarging masses.
Hence, any thyroid mass should be evaluated thoroughly.
Certain aspects of the patient's history are of particular
importance. The presence of conditions such as
Hashimoto's thyroiditis (an autoimmune condition),
Grave's disease, goiter, or a family history of medullary
carcinoma of the thyroid, all increase the risk of thyroid
cancer. A history of normal thyroid function is routine
in thyroid cancer patients, although hypothyroidism
may be present.
Physical examination of the neck in thyroid cancer
patients usually reveals a single or dominant nodule that
is at least 1 cm in diameter. This finding warrants a com-
prehensive evaluation, in most cases. Smaller nodules in
asymptomatic patients often are followed clinically and
by ultrasound. However, when a nodule is palpated, it
should be studied to determine whether it is isolated,
dominant, or simply one of many lesions within a multi-
nodular, goiterous thyroid gland. Nevertheless, it must be remembered that the presence of a multinodular goi-
ter does not rule out the possibility of cancer. In fact, as
many 7.5% of patients with a multinodular goiter may
also have thyroid cancer. 7 If palpable lymph nodes are
present in the neck in association with a solitary or dom-
inant thyroid mass, thyroid cancer should be suspected
(although it is not the only condition that can cause this
clinical picture). A nodule that is hard, immobile, fixed to surrounding structures, and poorly defined is also
more likely to be cancerous than a smooth, well circum -
scribed mobile nodule. Nodules larger than 2 cm are par-ticularly likely to harbor cancer.' In addition to examina-
tion of the thyroid and lymph nodes of the neck, the
larynx should be visualized in every case suspected of
having a thyroid abnormality, particularly a thyroid mass.
The evaluation of a patient with thyroid disease in-
volves not only physical examination, but also blood tests and imaging studies. Most physicians perform com-
mon thyroid function tests such as T3, T4, and TSH lev-
els. When malignancy is suspected, thyrotropin assay is
particularly helpful. Thyroglobulin levels often are ordered,
but they are not especially helpful when evaluating a
thyroid nodule; however, they are very useful as tumor
markers when recurrent thyroid cancer is suspected af-
ter total thyroidectomy and radiation. Many other thy-
roid blood tests may he ordered in selected cases includ-
ing antithyroid antibodies, serum calcitonin levels, RET
proto-oncogene screening, and other tests, the details
of which are beyond the scope of this article.
Thyroid imaging is performed routinely when masses
are identified. Thyroid ultrasound remains among the
most common studies. It is painless and involves no ra-
diation. Ultrasonography can detect lesions and deter-
mine whether nodules are cystic, solid, or mixed. Ultra-
sound is particularly valuable for its ability to measure
nodules accurately and allow nodule growth (or stabil-
ity) to be tracked over time. Although solid nodules on
ultrasound are more likely to be malignant than cystic
nodules, ultrasound cannot differentiate between ma-
lignant and benign solid nodules.' Ultrasound is very
helpful, however, in guiding fine needle aspirate biopsy
(FNAB), a minimally invasive office procedure for biop-
sying thyroid masses. In selected cases, CT and/or MRI
of the neck may be of value, particularly in assessing the
possibility of lymph node disease.
Thyroid uptake scans (thyroid scintigraphy) have been
used routinely in the evaluation of suspected thyroid can-
cer for more than a half century. Cancerous thyroid nod-
ules do not concentrate radio-labeled iodine tracer as well
as benign nodules. So benign nodules tend to be "hot,"
and malignant nodules tend to be 'old" on uptake scans. Unfortunately, accuracy of differentiation is not particu-
larly good. For example, only 10% to 15% of cold nod-
ules are actually cancerous; and cancer occurs in hot nod-ules with a frequency of about 4%. "'Nevertheless, thyroid
scanning is still useful particularly in selected patients, including particularly those with hypothyroidism, and
those with thyrotropin abnormalities.
FNAB is now the main stay of thyroid nodule diag-
nosis. The technique is fast, generally safe, inexpensive
and reasonably accurate, with a false-negative rate of
2.4% and false-positive rate of 1.2%, yielding an overall accuracy of over 95%h1 FNAB is not always definitive,
however. In addition to yielding reports of "benign" or
"malignant" disease, FNAB may also produce "nondi-
agnostic" specimens, and specimens reported as "sus-picious or indeterniinant." When definitive diagnosis
196 JOURNAL O SINGING
Care of the Professional Voice
cannot be established, thyroid surgery is required in
many cases, particularly if a diagnosis still has not been
reached on repeat FNAB with ultrasound guidance.
Nevertheless, FNAB has decreased the incidence of
avoidable thyroid surgery. When surgery is performed
for suspected thyroid cancer, cancer is found approxi-
mately 40% of the time, up from approximately 15% in
the days prior to FNAB.'2
THYROID PATHOLOGY AND ITS MANAGEMENT
Fortunately, most thyroid cancer falls into the "well differ-
entiated thyroid carcinoma" category. These include pap-
illary (79%) and follicular (13%) carcinoma.' 3 These tu-
mors arise from follicular cells of the thyroid gland and have
excellent survival rates. Papillary cancer ten year survival
rates are 90% to 95%, and those for follicular carcinoma
are 80% to 85%.' About 3% to 5% of all thyroid cancers
arise from the parafollicular C-cell and are medullary thy-roid carcinomas. The ten year survival rate for this tumor
is 65% to 80%) About 5% to 7% of thyroid cancers are pri-
mary lymphoma of the thyroid, and they have a five year
survival rate of about 50%.' Fortunately, only 2% to 5%
of thyroid cancers are anaplastic or undifferentiated thy-roid carcinoma. This lesion is associated with very poor
survival, usually measured in months.
Treatment for thyroid cancer depends upon the spe-cific pathology and will not be reviewed in detail here.
It may include thyroid surgery (partial or total removal
of the thyroid gland), radiation (radioactive iodine or external radiation), dissection and removal of lymph
nodes in the neck, or other modalities. In many cases,
thyroid function is ablated entirely, and thyroid replace-
ment therapy must be used for the rest of the patient's
life. Restoration of adequate systemic thyroid function
is usually possible, and this aspect of thyroid cancer usu-
ally will not end a singing career. It is also usually pos-
sible to remove the thyroid gland without injuring the la-
ryngeal nerves; laryngeal injury is a well recognized risk
of thyroid surgery and can occur even in the hands of
the best surgeon. Surgical experience, often combined with
the use of intraoperative nerve monitoring, provides the
best chance of avoiding injury to the nerves that move the vocal folds. Newer techniques such as minimally in-vasive thyroid surgery provide better cosmetic results
and also may be considered if a surgeon is highly expe-
rienced in this approach. However, for singers, preser-
vation of the laryngeal nerves is the main concern, sec-
ondary only to curing the cancer. Thyroid cancer is
certainly a serious matter, but it will not necessarily end
a vocal career.
NOTES
A. Wingo, T. Tong, and S. Boldien, "Cancer Statistics," CA: A
Cancer Journal for Clinicians 45, no. 1 (January/February
1995): 8-30.
2. L. J. DeGroot, E. L. Kaplan, M. McCormick, and F. M. Straus,
"Natural History Treatment, and Course of Papillary Thyroid
Carcinoma,' Journal of Clinical Endocrinology and Metabolism
71, no. 2 (August 1990): 414-424.
3. E. L. Mazzaferri, "Thyroid Cancer in Thyroid Nodules: Find-
ing a Needle in a Haystack:' American Journal of Medicine
93(1992): 359-369.
4. C. 0. Rice, "incidence of Nodules in the Thyroid,' Archives
ofSurgery 24 (1932): 505-515; J. D. Mortensen, L. B. Woiner,
and W. A. Bennett, 'Gross and Microscopic Findings in
Clinically Normal Thyroid Glands," Journal of Clinical
Endocrinology and Metabolism 15 (1955): 1270-1282.
5. R. 1.eeper, "Thyroid Carcinoma,' Medical Clinics of North
America 69, no. 5(1985): 1079-96.
6. H. Goepfert, W. J. Dichtel, and N. A. Samaan, "Thyroid
Cancer in Children and Teenagers:' Archives of Otolaryngology
110 (1985): 72-75; C. McHenry, M. Smith, A. Lawrence, et
al., "Nodular Thyroid Disease in Children and Adolescents,
Annals of Surgery 54 (1988):444-447; H. Hathaway, "Diagnosis
and Management of Thyroid Nodule:' Otolaryngology Clinics
of North America 23, no. 2 (April 1990): 303-337.
7. K. B. Koh and K. W. Chang, "Carcinoma in Multinodular
Goiter:' British Journal of Surgery 79 (1992): 266-267.
8. J. M. Miller, S. R. Kini, and J. I. Hamburger, "Diagnosis of
Malignant Follicular Neoplasm of the Thyroid by Needle
Biopsy:' Cancer 55 (1985): 2812-2817.
9. M. Ashcraft and A. VanHerle, "Management of Thyroid
Nodules 1' Head and Neck Surgery (January/February 1981):
216-227; M. Ashcraft and A. VanHerle, "Management of
Thyroid Nodules II," Head and Neck Surgery (March/April
1981): 297-322.
10. Ibid.
11. J. P. Campbell and H. C. Pillsbury, "Management of the Thy-
roid Nodule:' Head and Neck 11(1989): 414-425.
12. D. Caruso and E. L. Mazzaferri, "Fine Needle Aspiration
Biopsy in the Management of Thyroid Nodules:' Endo-
crinologist 1(1991): 194-197.
NOVEMBER/DECEMBER 2007 197
Robert T Sataloff, MD, DMA
13. S. A. Hundahl, 1. D. Fleming, A. M. Fregman, and H. R.
Menck, "A National Cancer Data Base Report on 53,856
Cases of Thyroid Carcinoma Treated in the U.S. 1985-1995:'
Cancer Journal 83 (1998): 2638-2648.
14, E. L. Mazzaferri and R. L. Young, "Papillary Thyroid
Carcinoma: A Ten-Year Follow-up Report on the Impact of
Treatment in 576 Patients,' American Journal of Medicine 70
(1981): 511-518; G. Emmerick, Q. 1)hu, A. Siperstein, et al.,
"Diagnosis, Treatment, and Outcome of Follicular Carcinoma:"
Cancer 72 (1993): 3287-3295; A. Shaha, T. R. Loree, and J. P.
Shah, "Prognostic Factors and Risk Group Analysis in
Follicular Carcinoma of the Thyroid," Surgery 118 (1995):
1131-1136.
15. Q. Y. Dub, J. J. Sancho, S. Greenspan, T. K. Hunt, M. Galante,
A. A. deLorimer, F. A. Conte, and 0. H. Clark, "Medullary
Thyroid Carcinoma: The Need for Early Diagnosis and Total
Thyroidectomy," Archives of Surgery 124, no. 10 (October
1989): 1206-1210.
16. D. L. Rasbach, M. S. Mondschein, N. L. Harris, et al., "Malig-
nant Lymphoma of the Thyroid Gland: A Clinical and
Pathologic Study of 20 Cases:' Surgery 6 (1985): 1166-1170;
J. I. Hamburger, J. M. Miller, and S. R. Kini, "Lymphoma of
the Thyroid:' Annals of Internal Medicine 99(1983): 685-689.
Robert 1. Sataloff, MD, DMA is Professor and Chairman of the Depart-
ment of Otolaryngology—Head and Neck Surgery and Associate Dean for Clinical Academic Specialties at Drexel University College of Med-icine. He is also on the faculty at Thomas Jefferson University, the University of Pennsylvania, Temple University, and the Academy of
Vocal Arts. Dr. Sataloff is Conductor of the Thomas Jefferson Univer-
sity Choir and Orchestra and Director of The Voice Foundation's Annual Symposium on Care of the Professional Voice. Dr. Sataloff is also a pro-
fessional singer and singing teacher. He holds an undergraduate
degree from Haverford College in Music Composition, graduated from
Jefferson Medical College, received a DMA in Voice Performance from
Combs College of Music, and completed his Residency in Otolaryn-
gology-Head and Neck Surgery at the University of Michigan. He also completed a Fellowship in Otology, Neurotology, and Skull Base Surgery at the University of Michigan. Dr. Sataloff is Chairman of the Board of Directors of The Voice Foundation and of the American Institute for
Voice and Ear Research. He is Editor-in-Chief of the Journal of Voice, Editor-in-Chief of the Ear, Nose and Throat Journal, an Associate Edi-tor of the Journal of Singing, and on the Editorial Board of Medical
Problems of Performing Artists and numerous major otolaryngology journals in the United States. Dr. Sataloff has written over 600 pub-lications, including thirty-six books. Dr. Sataloff's medical practice is limited to care of the professional voice and to otology/neurotology/skull
base surgery.