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Subhyoid midline ectopic thyroid tissue in the absence of normal thyroid gland
Subhyoid Midline Ectopic Thyroid Tissue in the Absence of Normal Thyroid Gland B~J
LUIS E. PARODI-HUECK
AND C. EVERETT
KOOP
T
HE FINDING OF THYROID TISSUE out of its normal anatomic position is unusual. Yet, ectopic thyroid tissue may be found at the foramen cecum, along the line of descent of the thyroglossal duct, particularly in the subhyoid region, in the mediastinum, pericardium, heart muscle, trachea, larynx, and esophagus. i In twenty years at the Children’s Hospital of Philadelphia, there have been but 10 patients with ectopic normal thyroid tissue. Two of these were lingual thyroids, one was the bulk of a teratoma behind the manubrium, and two were accessory thyroid tissue attached to or surrounding a thyroglossal duct cyst coexistant with a normal thyroid gland in a normal location. The remaining 5 patients, the subject of this paper, had ectopic thyroid tissue in the subhyoid position in the midline without any other thyroid tissue. EMBRYOLOGY The
thyroid
gland
appears
in the fourth
week
of embryonic
development
(L-2.5
cm.)
as a midline diverticulum of the pharyngeal floor between the first pair of pharyngeal pouches. The diverticulum becomes bilobed and descends into the neck retaining its attachment to the floor of the pharynx by the thyroglossal duct. The hyoid bone develops from the two halves of the second bran&al arch and fuses in the midline at or after the time of descent of the thyroid so that the thyroNglossal duct may vary in its relationship to the hyoid bone. By the sixth week of embryonic life, the elongated thyroglossal duct has become a solid stalk, usually undergoes degeneration and disappears. Its point of origin remains visible in some individuals as the foramen cecum.*J The question of how ectopic thyroid tissue develops has never been satisfactorily answered. It probably develops from thyroglossal outgrowth as does the main gland.1 Intracardiac thyroid tissue apparently is due to heteroplastic differentiation of foregut epithelium dislocated into the dorsal mesocardium during development. This may aho account for the rare occurrence of esophageal thyroid tissue.4 CASE
REPORTS
Our five patients were asymptomatic except for the presence of a mass which had been noted for periods ranging from 5 months to 5% years before surgical consultation was requested. In each instance, the presumptive preoperative diagnosis was thyroglossal duct cyst. In each patient at operation, the lesion was recognized as probably being thyroid and not thyroglossal duct cyst, an impression that was co,nfirmed by histologic examination on frozen section. In each instance, a search was made for normal thyroid, first by palpation From the Surgical Clinic of The Children’s HospitaE of Philadelphia and The Hurri.s~n Department of Surgical Research, The Uniuersity of Pennsylvania School of Medicine. Lurs E. PARODI-HUECK, M.D.: Formerly Surgical Fellow, Children’s Hospital of PhiladeZphiu, Philadelphia, Pennsylvania. C. EVERETT Koo~, M.D., Sc.D.: Surgeon-in-Chief, Children’s Hospital of Philadelphia; Professor of Pediatric Surgery, University of Pennsyluaniu, Philadelphia, Pennsylvania. 710
JOURNAL OF PEDIATRICSURGERY,VOL. 3, No. 6 (DECEMBER), 1968
SUBHYOID
MIDLINE
ECTOPIC
THYROID
TISSUE
711
Fig. 1.-Postoperative
then by exploration of the neck, either through a separate incision or through the small incision already made for excision of the thyroglossal lesion. All patients were treated in identical fashion inasmuch as no thyroid tissue was found in the normal anatomic location. The thyroid tissue was bisected vertically in the midline with hemostasis being secured by individual ligation of bleeders with sutures of 3-O catgut. The halves of the thyroid tissue were then implanted in pouches made by elevating the strap muscles bilaterally. In this position, the thyroid halves were secured with mattress sutures of 3-O chromic catgut as described by Crosss Thyroid scanning was carried out in two patients postoperatively using technetium pertechnetate as the scanning agent (Fig. 1). 5 patients in Table 1, to which have been 2 patients in thyroglossal duct cysts but
in the necks children, particularly those by most examiners to be thyroglossal duct 17 instances have been a midline subhyoid to be ectopic thyroid In only 4 these patients by thyroid scanning; as thyroglossal duct cysts. the 13 patients 5 were diagnosed on the operating In the other at the operating of the midline 2 had thyroid in Table 2. In of on swallowing,
712
PARODI-HUE%
Table 1 .-Author’s
Age
Sex
Duration
Size
Midline Ectopic
Frozen Section Thyroid
1
8 yr.
F
1 yr.
3 cm.
Yes
2
5yr.
F
birth
1 cm.
Yes
3 4 5
7 yr. 3 yr. 7yr.
F M F
1% yr. 1 wk. 1 yr.
2 cm. 1.5 cm. 1.5 cm.
Yes Yes Yes
6 7
11 mo. 5 yr.
M F
Ectopic
KOOP
Cares of Subhyoid Ectopic Thyroid Tissue
C&se No.
AND
Thyroid
5 mo. 2 yr.
In Thyroglossal
1 cm. 2 cm.
Neck Exploration
Operation
Normal Thyroid
Single incision Single incision
Bisected
No
Bisected
No
Yes Yes Yes
Bisected Bisected Bisected
No
Excised Excised
Yes Yes
Only
NO
No
Duct Cyst No No
No No
the symptoms of hypothyroidism took time to appear because there was ectopic thyroid tissue in other locations. In 2 of these, the accessory thyroid tissue was in the lingual position. In one other, the subhyoid thyroid was bisected and left behind and the lingual thyroid tissue was excised.l” In the 20 years covered by this report, we operated upon 169 patients with thyroglossal duct cysts and sinuses. Most of these were cysts that theoretically were indistinguishable from subhyoid ectopic thyroid tissue. To obtain an accurate preoperative diagnosis would have entailed the performance of a number of thyroid scanning procedures but the ease with which this procedure can be performed and its low risk convinces us that this is the proper method of management. Table 2.-22
Collected Cases of Subhyoid Ectopic Thyroid in the Absence of Normal Thyroid Gland Left in
Excised
Gross and Connerly, 19406 Gross, 1953 5 2 cases McGirr, 1954’ Dimson, 1956s Grieve, 19599 Haller and Williams, 1959lO Quigley et al, 1962 Long et al., 196412 Leland, 19641s Klopp and Kirson 196614 S cases Updhyaha and Bhimsen, 1966i5 Bosen and Walfish, 196716 Rosen and Walfish, 196716 Lewis and Holleran, 1968”* Parodi-Hueck and Koon. 1968.5 cases *No operation.
No No
X
No
X
No No
X
Ectopio
Position
Bisected
x
No
x
Yes Yes No No Yes No Yes No No
X X
X X
x X
X X
X
SUBHYOIB MIDLINE
ECIOPIC
713
THYBOID TISSUE
Obviously there are midline masses where the diagnosis of thyroglossal duct cyst is quite clear such as when there is concomitant inilammation, or when there has been accurate observation of fluctuation in size. In such instances the experienced diagnostician might well elect not to perform a scan. We have used the nuclide technetium-9gm (photon 14 KeV, half-life 6 hours), which although not naturally metabolized by the thyroid gland is transiently concentrated there. A dose of 1-2 millicuries is the normal adult dose and is reduced according to weight in chi1dren.l” The image quality is as good or better than with 13lI. There is a great reduction in radiation dose both to the gland and the whole body with technetium as compared to 1311. The ggmTc scans can be made three times faster than with lx11 and in one visit, In those instances where a scan is not possible or deemed necessary, no midline mass should be excised without close inspection, including its bisection to be certain that it is not thyroid tissue. The great advantage of the scan is not only the accurate diagnosis of thyroid tissue in the midline mass, but the confirmation of a thyroid gland in the normal anatomical position. If normal thyroid gland is present, there is no need to preserve the subhyoid ectopic tissue but on the other hand, if no normal thyroid is present, it is absolutely essential to preserve the ectopic tissue. The operative procedure described presents no difficulties and the cosmetic results are excellent.’
SUMMARY Subhyoid ectopic thyroid tissue existing in the absence of a normal thyroid gland is a rare finding. The preoperative clinical impression of this lesion is nearly always thyroglossal duct cyst and its excision results in myxedema. Radioactive scan of subhyoid midline spherical masses is the only means of preoperative assessment of ectopic thyroid tissue and the presence of normal thyroid gland as well. In the absence of a scan, suspected thyroglossal duet cysts should he bisected at the time of surgery to prove they are not thyroid tissue. No midline subhyoid ectopic thyroid should be excised unless there is a normal thyroid gland. SUMMARIO IN INTERLINGUA Le autores ha addite al 17 cases jam reportate ectopic
centralmente
usualmente
sublingual
diagnosticate
resultato-si
le “cyste”
subhyoide
massas spheric
tissu thyroide absentia un cyste mesura *Since
erroneemente
de un scrutinage demonstra preparing
in le litteratura
de un normal
coma
es excidite-de
sed etiam
de1 ducto
in absentia
cyste
de1 ducto
myxedema.
preoperatori,
thyroglossal
deherea
que il se tracta
glandula
non solmente thyroide
Le lesion es con le ultime
radioactive
de omne
trova le presentia
si un tales presente.
de
In le
nulle lesion mesolineal que es reguardate coma esser excidite sin que illo es bisecate. Si iste
de tissu thyroide,
this paper one child has developed
at the bisected buried ectopic thyroid. reducing the size of the thyroid tissue.
thyroglossal,
Un scrutinage
in le area de1 linea central delinea le normal
cinque noves de thyroide
glandula thyroide.
le massa
non dehe
a cosmetically
She has been given thyroid
esser excidite
significant swelling
extract
as a means of
714 ante
PARODI-HUECK que
plantation corrective.
le presentia de1 bisecate
de un normal glandula
glandula
ectopic
infra
thyroide musculos
ha
essite es
un
AND KOOP
demonstrate. satisfacente
Le
im-
method0
REFZRENCES 1. Willis,
R. A.: The
Borderland
of Em-
bryology and Pathology. London, Butterworth, 1958. 2. Pollock, W., and Stevenson, E.: Cysts and sinuses of the thyroglossal duct. Amer. J. Surg. 112:!225, 1966. 3. Potter, E. L.: Pathology of and the Infant, ed. 2. Chicago, Medical Publishers, 1962. 4. Dische, S., and Berg, P. K.: tigation of the thyroglossal tract radioisotope scan. Clin. Radiol.
the Fetus Yearbook An invesusing the 14:298,
1963. 5. Gross, R. E.: The Surgery of Infancy and Childhood, ed. 1. Philadelphia and London, W. B. Saunders Co., 1953. 6. Gross, R. E., and Connerley, M. L.: Thyroglossal cysts and sinuses; Study report of 198 cases. New Eng. J. of Med. 233:616, 1940. 7. MC Girr, E. M., and Hutchison, J. H.: The value of radioiodine (1131) in juvenile myxoedema due to ectopic thyroid tissue. Arch. Dis. Child. 29:561, 1954. 8. Dimson, S. B.: Juvenile myxoedema due to removal of ectopic thyroid. Proc. Roy. Sot. Med. 49:941, 1956. 9. Grieve, J.: A subhyoid median ectopic thyroid. Arch. Dis. Child. 34:18, 1959. 10. Hailer, J. A., Jr., and Williams, G. R.: Isolated midline thyroid in the thyroglossal duct. Surgery 46:437, 1959. 11. Quigley, W. F., Williams, L. F., and Hughes, C. W.: Surgical management of subhyoid median ectopic thyroid. Ann.
Surg. 155:305, 1962. 12, Long, R. T. L., Evans, A. M., and Beggs, J. H.: Surgical management of ectopic thyroid: Report of a case with simultaneous lingual and subhyoid median ectopic thyroid. Ann. Surg. 160:824, 1964. 13. Leland, S.: Ectopic thyroid tissue. J. Okla. Med. Assoc. 57:385, 1964. 14. Klopp, C. T., and Kirson, S. M.: Therapeutic problems with ectopic noncancerous follicular thyroid tissue in the neck: 18 case reports according to etiologic factors. Ann. Surg. 163:653, 1966. 15. Upadhyaya, P., Rao, V. B., and Rao, B. N.: Adenomatous change in a median cervical ectopic thyroid. Int. Surg. 45:629, 19686. 16. Rosen, I. B., and Walfish, P. G.: The subhyoid ectopic median thyroid. Canad. Med. Assoc. J. 96544, 1967. 17. Lewis, M. I., and Holleran, W. M.: Ectopic thyroid gland in children. Amer. J. Surg. 115:688, 1968. 18. Fish, J., and Moore, R. M.: Ectopic thyroid tissue and ectopic thyroid carcinoma: Review of the literature and report of a case. Ann. Surg. 157:212, 1963. 19. Sanders, T. P., and Kuhl, D. E.: Technetium pertechnetate as a thyroid scanning agent. Accepted for publication in Radiology, 1968. 20. Snedecon, P. A., and Grosho.ng, L. E.: Carcinoma of the thyroglossal duct. Surgery 58:969, 1965.
LUIS E. PARODI-HUECK
AND C. EVERETT
KOOP
T
HE FINDING OF THYROID TISSUE out of its normal anatomic position is unusual. Yet, ectopic thyroid tissue may be found at the foramen cecum, along the line of descent of the thyroglossal duct, particularly in the subhyoid region, in the mediastinum, pericardium, heart muscle, trachea, larynx, and esophagus. i In twenty years at the Children’s Hospital of Philadelphia, there have been but 10 patients with ectopic normal thyroid tissue. Two of these were lingual thyroids, one was the bulk of a teratoma behind the manubrium, and two were accessory thyroid tissue attached to or surrounding a thyroglossal duct cyst coexistant with a normal thyroid gland in a normal location. The remaining 5 patients, the subject of this paper, had ectopic thyroid tissue in the subhyoid position in the midline without any other thyroid tissue. EMBRYOLOGY The
thyroid
gland
appears
in the fourth
week
of embryonic
development
(L-2.5
cm.)
as a midline diverticulum of the pharyngeal floor between the first pair of pharyngeal pouches. The diverticulum becomes bilobed and descends into the neck retaining its attachment to the floor of the pharynx by the thyroglossal duct. The hyoid bone develops from the two halves of the second bran&al arch and fuses in the midline at or after the time of descent of the thyroid so that the thyroNglossal duct may vary in its relationship to the hyoid bone. By the sixth week of embryonic life, the elongated thyroglossal duct has become a solid stalk, usually undergoes degeneration and disappears. Its point of origin remains visible in some individuals as the foramen cecum.*J The question of how ectopic thyroid tissue develops has never been satisfactorily answered. It probably develops from thyroglossal outgrowth as does the main gland.1 Intracardiac thyroid tissue apparently is due to heteroplastic differentiation of foregut epithelium dislocated into the dorsal mesocardium during development. This may aho account for the rare occurrence of esophageal thyroid tissue.4 CASE
REPORTS
Our five patients were asymptomatic except for the presence of a mass which had been noted for periods ranging from 5 months to 5% years before surgical consultation was requested. In each instance, the presumptive preoperative diagnosis was thyroglossal duct cyst. In each patient at operation, the lesion was recognized as probably being thyroid and not thyroglossal duct cyst, an impression that was co,nfirmed by histologic examination on frozen section. In each instance, a search was made for normal thyroid, first by palpation From the Surgical Clinic of The Children’s HospitaE of Philadelphia and The Hurri.s~n Department of Surgical Research, The Uniuersity of Pennsylvania School of Medicine. Lurs E. PARODI-HUECK, M.D.: Formerly Surgical Fellow, Children’s Hospital of PhiladeZphiu, Philadelphia, Pennsylvania. C. EVERETT Koo~, M.D., Sc.D.: Surgeon-in-Chief, Children’s Hospital of Philadelphia; Professor of Pediatric Surgery, University of Pennsyluaniu, Philadelphia, Pennsylvania. 710
JOURNAL OF PEDIATRICSURGERY,VOL. 3, No. 6 (DECEMBER), 1968
SUBHYOID
MIDLINE
ECTOPIC
THYROID
TISSUE
711
Fig. 1.-Postoperative
then by exploration of the neck, either through a separate incision or through the small incision already made for excision of the thyroglossal lesion. All patients were treated in identical fashion inasmuch as no thyroid tissue was found in the normal anatomic location. The thyroid tissue was bisected vertically in the midline with hemostasis being secured by individual ligation of bleeders with sutures of 3-O catgut. The halves of the thyroid tissue were then implanted in pouches made by elevating the strap muscles bilaterally. In this position, the thyroid halves were secured with mattress sutures of 3-O chromic catgut as described by Crosss Thyroid scanning was carried out in two patients postoperatively using technetium pertechnetate as the scanning agent (Fig. 1). 5 patients in Table 1, to which have been 2 patients in thyroglossal duct cysts but
in the necks children, particularly those by most examiners to be thyroglossal duct 17 instances have been a midline subhyoid to be ectopic thyroid In only 4 these patients by thyroid scanning; as thyroglossal duct cysts. the 13 patients 5 were diagnosed on the operating In the other at the operating of the midline 2 had thyroid in Table 2. In of on swallowing,
712
PARODI-HUE%
Table 1 .-Author’s
Age
Sex
Duration
Size
Midline Ectopic
Frozen Section Thyroid
1
8 yr.
F
1 yr.
3 cm.
Yes
2
5yr.
F
birth
1 cm.
Yes
3 4 5
7 yr. 3 yr. 7yr.
F M F
1% yr. 1 wk. 1 yr.
2 cm. 1.5 cm. 1.5 cm.
Yes Yes Yes
6 7
11 mo. 5 yr.
M F
Ectopic
KOOP
Cares of Subhyoid Ectopic Thyroid Tissue
C&se No.
AND
Thyroid
5 mo. 2 yr.
In Thyroglossal
1 cm. 2 cm.
Neck Exploration
Operation
Normal Thyroid
Single incision Single incision
Bisected
No
Bisected
No
Yes Yes Yes
Bisected Bisected Bisected
No
Excised Excised
Yes Yes
Only
NO
No
Duct Cyst No No
No No
the symptoms of hypothyroidism took time to appear because there was ectopic thyroid tissue in other locations. In 2 of these, the accessory thyroid tissue was in the lingual position. In one other, the subhyoid thyroid was bisected and left behind and the lingual thyroid tissue was excised.l” In the 20 years covered by this report, we operated upon 169 patients with thyroglossal duct cysts and sinuses. Most of these were cysts that theoretically were indistinguishable from subhyoid ectopic thyroid tissue. To obtain an accurate preoperative diagnosis would have entailed the performance of a number of thyroid scanning procedures but the ease with which this procedure can be performed and its low risk convinces us that this is the proper method of management. Table 2.-22
Collected Cases of Subhyoid Ectopic Thyroid in the Absence of Normal Thyroid Gland Left in
Excised
Gross and Connerly, 19406 Gross, 1953 5 2 cases McGirr, 1954’ Dimson, 1956s Grieve, 19599 Haller and Williams, 1959lO Quigley et al, 1962 Long et al., 196412 Leland, 19641s Klopp and Kirson 196614 S cases Updhyaha and Bhimsen, 1966i5 Bosen and Walfish, 196716 Rosen and Walfish, 196716 Lewis and Holleran, 1968”* Parodi-Hueck and Koon. 1968.5 cases *No operation.
No No
X
No
X
No No
X
Ectopio
Position
Bisected
x
No
x
Yes Yes No No Yes No Yes No No
X X
X X
x X
X X
X
SUBHYOIB MIDLINE
ECIOPIC
713
THYBOID TISSUE
Obviously there are midline masses where the diagnosis of thyroglossal duct cyst is quite clear such as when there is concomitant inilammation, or when there has been accurate observation of fluctuation in size. In such instances the experienced diagnostician might well elect not to perform a scan. We have used the nuclide technetium-9gm (photon 14 KeV, half-life 6 hours), which although not naturally metabolized by the thyroid gland is transiently concentrated there. A dose of 1-2 millicuries is the normal adult dose and is reduced according to weight in chi1dren.l” The image quality is as good or better than with 13lI. There is a great reduction in radiation dose both to the gland and the whole body with technetium as compared to 1311. The ggmTc scans can be made three times faster than with lx11 and in one visit, In those instances where a scan is not possible or deemed necessary, no midline mass should be excised without close inspection, including its bisection to be certain that it is not thyroid tissue. The great advantage of the scan is not only the accurate diagnosis of thyroid tissue in the midline mass, but the confirmation of a thyroid gland in the normal anatomical position. If normal thyroid gland is present, there is no need to preserve the subhyoid ectopic tissue but on the other hand, if no normal thyroid is present, it is absolutely essential to preserve the ectopic tissue. The operative procedure described presents no difficulties and the cosmetic results are excellent.’
SUMMARY Subhyoid ectopic thyroid tissue existing in the absence of a normal thyroid gland is a rare finding. The preoperative clinical impression of this lesion is nearly always thyroglossal duct cyst and its excision results in myxedema. Radioactive scan of subhyoid midline spherical masses is the only means of preoperative assessment of ectopic thyroid tissue and the presence of normal thyroid gland as well. In the absence of a scan, suspected thyroglossal duet cysts should he bisected at the time of surgery to prove they are not thyroid tissue. No midline subhyoid ectopic thyroid should be excised unless there is a normal thyroid gland. SUMMARIO IN INTERLINGUA Le autores ha addite al 17 cases jam reportate ectopic
centralmente
usualmente
sublingual
diagnosticate
resultato-si
le “cyste”
subhyoide
massas spheric
tissu thyroide absentia un cyste mesura *Since
erroneemente
de un scrutinage demonstra preparing
in le litteratura
de un normal
coma
es excidite-de
sed etiam
de1 ducto
in absentia
cyste
de1 ducto
myxedema.
preoperatori,
thyroglossal
deherea
que il se tracta
glandula
non solmente thyroide
Le lesion es con le ultime
radioactive
de omne
trova le presentia
si un tales presente.
de
In le
nulle lesion mesolineal que es reguardate coma esser excidite sin que illo es bisecate. Si iste
de tissu thyroide,
this paper one child has developed
at the bisected buried ectopic thyroid. reducing the size of the thyroid tissue.
thyroglossal,
Un scrutinage
in le area de1 linea central delinea le normal
cinque noves de thyroide
glandula thyroide.
le massa
non dehe
a cosmetically
She has been given thyroid
esser excidite
significant swelling
extract
as a means of
714 ante
PARODI-HUECK que
plantation corrective.
le presentia de1 bisecate
de un normal glandula
glandula
ectopic
infra
thyroide musculos
ha
essite es
un
AND KOOP
demonstrate. satisfacente
Le
im-
method0
REFZRENCES 1. Willis,
R. A.: The
Borderland
of Em-
bryology and Pathology. London, Butterworth, 1958. 2. Pollock, W., and Stevenson, E.: Cysts and sinuses of the thyroglossal duct. Amer. J. Surg. 112:!225, 1966. 3. Potter, E. L.: Pathology of and the Infant, ed. 2. Chicago, Medical Publishers, 1962. 4. Dische, S., and Berg, P. K.: tigation of the thyroglossal tract radioisotope scan. Clin. Radiol.
the Fetus Yearbook An invesusing the 14:298,
1963. 5. Gross, R. E.: The Surgery of Infancy and Childhood, ed. 1. Philadelphia and London, W. B. Saunders Co., 1953. 6. Gross, R. E., and Connerley, M. L.: Thyroglossal cysts and sinuses; Study report of 198 cases. New Eng. J. of Med. 233:616, 1940. 7. MC Girr, E. M., and Hutchison, J. H.: The value of radioiodine (1131) in juvenile myxoedema due to ectopic thyroid tissue. Arch. Dis. Child. 29:561, 1954. 8. Dimson, S. B.: Juvenile myxoedema due to removal of ectopic thyroid. Proc. Roy. Sot. Med. 49:941, 1956. 9. Grieve, J.: A subhyoid median ectopic thyroid. Arch. Dis. Child. 34:18, 1959. 10. Hailer, J. A., Jr., and Williams, G. R.: Isolated midline thyroid in the thyroglossal duct. Surgery 46:437, 1959. 11. Quigley, W. F., Williams, L. F., and Hughes, C. W.: Surgical management of subhyoid median ectopic thyroid. Ann.
Surg. 155:305, 1962. 12, Long, R. T. L., Evans, A. M., and Beggs, J. H.: Surgical management of ectopic thyroid: Report of a case with simultaneous lingual and subhyoid median ectopic thyroid. Ann. Surg. 160:824, 1964. 13. Leland, S.: Ectopic thyroid tissue. J. Okla. Med. Assoc. 57:385, 1964. 14. Klopp, C. T., and Kirson, S. M.: Therapeutic problems with ectopic noncancerous follicular thyroid tissue in the neck: 18 case reports according to etiologic factors. Ann. Surg. 163:653, 1966. 15. Upadhyaya, P., Rao, V. B., and Rao, B. N.: Adenomatous change in a median cervical ectopic thyroid. Int. Surg. 45:629, 19686. 16. Rosen, I. B., and Walfish, P. G.: The subhyoid ectopic median thyroid. Canad. Med. Assoc. J. 96544, 1967. 17. Lewis, M. I., and Holleran, W. M.: Ectopic thyroid gland in children. Amer. J. Surg. 115:688, 1968. 18. Fish, J., and Moore, R. M.: Ectopic thyroid tissue and ectopic thyroid carcinoma: Review of the literature and report of a case. Ann. Surg. 157:212, 1963. 19. Sanders, T. P., and Kuhl, D. E.: Technetium pertechnetate as a thyroid scanning agent. Accepted for publication in Radiology, 1968. 20. Snedecon, P. A., and Grosho.ng, L. E.: Carcinoma of the thyroglossal duct. Surgery 58:969, 1965.