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Cysts and Sinuses of the Neck of Thyroglossal and Branchial Origin
Cysts and Sinuses of the Neck of Thyroglossal and Branchial Origin ALEXANDER H. BILL, JR., M.D., F.A.C.S. *
one sees a child or an adult with a congenital cyst or sinus of the neck, one can ordinarily predict from the position of the lesion its relationship to other structures and what extensions may exist. A simple knowledge of the embryology of the neck is necessary for an understanding of these relationships and for the adequate surgical removal of such a cyst or sinus. WHEN
Fig. 525. Areas in which we expect to find remnants of the thyroglossal duct, the second branchial cleft, and the first branchial cleft.
As a rule, one can consider that the cysts or fistulas in the midline of the neck, from the level of the thyroid gland upward, are remnants of the thyroglossal duct. A cyst or sinus appearing in the lateral portion of the neck will, as a rule, be a remnant of incomplete closure of one of the branchial clefts, usually the second, but occasionally the first (Fig. 525).
* Attending Surgeon, Children's Orthopedic Hospital; Clinical Associate in Surgery, School of Medicine, University of Washington, SeatUe. 1599
1600
Alexander H. Bill, Jr. EMBRYOLOGY OF THE THYROGLOSSAL DUCT
Early in fetal life the major part of the thyroid gland, and indeed, some say all of the thyroid gland, starts is migration downward to its adult position from a point at the base of the tongue, known as the foramen cecum. The anlage of the gland migrates down in the midline of the neck anterior to the larynx and between the developing ends of the hyoid bone until its final resting place is reached. As the anlage descends, a tube from the base of the tongue is pulled down after it. This remains open until the gland reaches its normal level and then loses its lumen. It may occasionally remain open as a duct, in which case secretions from the cells lining it may flow back up into the mouth or, if the duct becomes plugged, will form a cystic swelling. Evidently the tube, or thyroglossal duct, remains open all the way up to the base of the tongue if it remains patent at all. This fact is of utmost importance if the surgeon is to remove a thyroglossal cyst completely, without the danger of recurrence. As noted above, the hyoid bone is formed from two halves which start their development from the sides and then fuse in the midline. The fusion of the bone transects the thyroglossal duct in such a way that the duct runs either directly through the substance of the bone or else lies closely applied to its upper or lower surface. Therefore when the thyroglossal duct remains patent, it is impossible to dissect out this part of it without removal of the center of the hyoid bone. While most of the cysts derived from the thyroglossal duct contain mucus, in a few cases the thyroid gland will not have completed its descent and the mass believed to be a cyst is actually the thyroid itself which has stopped somewhere along its course down to the lower neck. Recognition of this fact may at times prevent the removal of the entire thyroid gland. EMBRYOLOGY OF THE BRANCHIAL CLEFTS
As the fetus is forming, the sides of the neck present a series of folds. The prominence of the first fold, or "arch" as it is known, changes shape to form the structures of the cheek including the mandible and part of the external ear; while the second arch contributes to the external ear and then coalesces with the lower arches to form a smooth contour down the side of the neck. The folds between the arches are known as "branchial clefts." The first branchial cleft, which lies between the first and second arches, normally remains partly open to form the eustachian tube and the external auditory canal. The second branchial cleft, lying between the second and third arches, normally disappears. A glance at Figure 526 will show that the line of closure of the first branchial cleft will underlie a line extending from just below the center of the mandible back around the angle of the jaw and up to the external auditory canal. The base of the line of closure of the second branchial cleft will extend
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from a point on the lower anterior border of the sternocleidomastoid muscle slightly posteriorly and upward to end at the upper pole of the tonsillar fossa. The line of closure goes through the fork formed by the bifurcation of the internal and external carotid arteries. At times the depths of either the first or second cleft will not coalesce completely and
:'+.'-"--Carotid art
Fig. 526. Embryological derivation of lower face, ear and upper neck from the first and second branchial arches. The theoretical lines of closure of the first and second branchial clefts are shown in dotted lines. (Reprinted from Annals of Surgery, by permission.)
will therefore leave a tract. This may then either distend as a cyst, if there are no internal or external openings, or will drain either internally or externally, if there is such an opening. TREATMENT OF THYROGLOSSAL DUCT CYSTS AND FISTULAS
Any mass appearing in or near the midline of the neck, especially if it is cystic, and also if it appears to be infected, must be suspected of being a thyroglossal duct cyst. While the most usual place for such a cyst is in the midline between the level of the hyoid bone and the thyroid gland, reference to Figure 527 will show that these cysts can be found above this level. As one would expect from the embryology, the cysts do not usually communicate with the skin (Fig. 528). Occasionally, where there has been infection which has broken out to the surface, an epithelial-lined tract will become established between the cyst and the skin of the midline of the neck (Fig. 529). This, typically, will discharge purulent material or mucus.
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Lesions which may be confused with a thyroglossal duct cyst include dermoid cysts, which in comparison are relatively rare and often cannot be differentiated prior to operation. In the upper neck and in the submental region one may occasionally find a midline mass which proves to be a lymph node. As we have mentioned above, a solid mass may prove to be thyroid tissue which owes its presence in the upper neck to its incomplete descent. Most authorities recommend that a thyroglossal duct cyst be removed because sooner or later all, or certainly almost all, of these lesions become infected. This is understandable when one considers that thyroglossal
Fig. 527. Location in 22 cases of thyroglossal duct cysts or fistulas to show the relative frequency of location in the usual type of case.
duct cysts are connected by a patent duct with the back of the tongue and that infection may be introduced at any time through this avenue. Technique of Removal of Thyroglossal Duct Cyst or Sinus
A thyroglossal duct cyst or sinus should be removed at the early convenience of the patient and surgeon. If the lesion is, already infected, incision and drainage should be carried out and the infection allowed to subside. The operation which has been most consistently successful was evidently first suggested by Schlange 6 in 1893. To Sistrunk,7 however, must go the credit for the present day technique. The essential part of the technique, described by him in 1920, lies in the excision of the central
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1 or 2 cm. of the hyoid bone and then coring out a piece of tissue extending from the hyoid bone backward and upward to the base of the tongue at the foramen cecum.
Fig. 528. Child with infected thyroglossal duct cyst in the most frequently found position.
Fig. 529. Child with a draining thyroglossal duct fistula low in the neck.
The operation is performed with the patient under general anesthesia and with the neck extended (Fig. 530). A transverse incision is then made over the cyst or, if a fistula is present, a transverse ellipse of skin
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Fig. 530. Technique of removal of thyroglossal duct cyst or fistula. A, The incision should be transverse or transverse-elliptical. E, The cyst or fistula is dissected upward to the level of the hyoid bone. C, The hyoid bone is freed of its muscular attachments for 1 cm. on each side of the midline, and the bone is then cut on each side. D, With the hyoid still attached superiorly at its center, a 0.5 cm. core of tissue is removed up to the base of the tongue. This point is identified by the finger holding the base of the tongue forward and up toward the wound. The dissection is stopped at the whitish undersurface of the mucous membrane. The core of tissue will contain the upper portion of the thyroglossal duct.
is removed. The cyst or fistula is then dissected on all sides and its connection upward to the hyoid bone included in the dissection. This connection is as a rule fairly superficial and actually lies between the thyrohyoid muscles. When the dissection reaches the hyoid bone the muscular connections above and below the hyoid are cut in order to free the bone
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for a distance of about 1 cm. on either side of the midline. The attachments of the very center of the bone are left undisturbed since the duct is included in this tissue. An instrument is passed behind the hyoid on each side of the midline to free the bone in these areas. A cut is made through the bone about 1 cm. lateral to the center on each side, using small bone-cutting forceps. This, then, leaves the central 1 or 2 cm. of the bone freed from its lateral portions and attached in the middle of its posterior and superior aspects. With the freed central portion of the bone held in an instrument, a 0.5 cm. core of tissue is now dissected up toward the base of the tongue. This point can be identified by the forefinger of the anesthetist or of an assistant, which is placed at the base of the tongue and then pushes the tongue upward toward the wound. The dissection is stopped at the whitish membrane which indicates that the under side of the mucosal surface of the tongue has been reached. The core of tissue containing the upper portion of the duct is then cut off and the muscles of the tongue are reapproximated with a few interrupted sutures. The cut ends of the hyoid bone need not be approximated but the other muscle layers are closed with interrupted sutures. It has been our policy to leave a small drain up as far as the hyoid bone, and we have found that a rubber band serves very well for this purpose. The skin and subcutaneous tissues are closed around the drain in the usual manner, and a dressing is applied. The drain is removed in 24 hours. Pitfalls in the Operative Technique
While in the average case the technique described above is straightforward and without complications, yet the operator must be on the alert for variations in the course of the duct and for the possibility of thyroid tissue being present in place of a cyst. We have seen cases in which the cyst extended laterally from its midline position. In one instance this extended back to the side of the larynx. We have also seen cases in which the extension of the cyst appeared above the hyoid bone. These variations of anatomy must be anticipated and dealt with by accurate and careful dissection (Fig. 531). Possibly the most important pitfall is the assumption that there is no duct above the hyoid bone. This duct is often so small as to defy recognitionon dissection, yet the central portion of the hyoid bone and with it a core of tissue back to the tongue must be removed. As evidence of this we recently reviewed eight cases of thyroglossal duct cyst treated in a Seattle hospital several years ago. These cases had in common the fact that the center of the hyoid bone had not been removed. In seven of these eight cases recurrence had appeared within one year I The use of an up-and-down skin incision rather than a transverse one will always lead to a distressing scar that will contract and draw the normal contour of the neck out of shape. If the cyst or fistula is low in
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the neck, it may be difficult or impractical to remove the upper portion of the tract through the original transverse incision. In these circumstances a second transverse incision at the level of the hyoid bone will allow removal of the upper tract and yet will give a good cosmetic result. RECOGNITION AND TREATMENT OF BRANCHIOGENIC ANOMALIES
The differential diagnosis of a lateral mass· or a fistula in the neck is more difficult than when the mass is in the midline. If the mass can be shown to be cystic, it is most likely to be a cyst derived from one of the
"liMtFig. 531. Variations in position or pathology in 4 unusual cases of thyroglossal duct anomaly. a, Cyst presenting in submental region and under tongue. b, Mass proved to be thyroid tissue just anterior to hyoid bone. c, Thyroglossal duct cyst with a lateral extension going around to side of larynx. d, Unusual course of duct.
branchial clefts. In a child, however, it could possibly be a cystic hygroma. Such a mass will be multilocular as a rul~, which will serve to make the diagnosis at operation. Another large group of lateral masses in the neck include inflammatory or neoplastic enlargements of the lymph nodes. The history is often of some help in arriving at the diagnosis of a cyst since many of these will have been present for a long time with no evidence of inflammation. Inflammation may, of course, be superimposed. Likewise, a branchiogenic sinus or fistula may be difficult to differentiate from one with an inflammatory origin. Again the history
1 j
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may help since a congenital branchiogenic sinus or fistula will most likely have been present since birth, with seepage of mucus from the opening ever since the parents can remember. In any of these lesions tuberculosis needs to be considered and ruled out. AnOInalies of the Second Branchial Cleft
A cystic mass or a sinus presenting along the anterior border of the sternocleidomastoid muscle in the lower half of the neck will, in general, represent a remnant of the second branchial cleft. Reference to Figure 532 will show the possible abnormalities with either a sinus-like opening or a cyst. The base of the second branchial cleft appears to leave remnants in the same manner that a hernial sac or a hydrocele are remnants of the processus vaginalis. By this we mean that an isolated portion of
Cyst with pharyngeal openinq Extel"nal sinus
Fig. 532. Schematic outline of possible anomalies derived from the second branchial cleft. (Modified and reprinted from Annals of Surgery, by permission.)
the base of the cleft may stay open as a cyst, or that one end may stay open for varying distances as a sinus, or, finally, that the entire base of the cleft may remain patent as a fistula from the upper tonsillar fossa to the lower neck. The remnants of the second branchial cleft differ from those of the thyroglossal duct to the extent that the internal, or upper, end of the branchial cleft remnant does not always have a lumen. If the upper extension of the tract stays open, it will pass upward through the bifurcation of the internal end of the common carotid arteries. If a sinus tract presents itself on the anterior border of the lower portion of the sternocleidomastoid muscle, this tract may extend only for a centimeter or two, or it may extend all the way up to the upper tonsillar fossa on the same side (Fig. 533). Similarly, a cystic mass presenting just
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anterior to the sternocleidomastoid muscle along its lower or middle third may be a blind cyst, or it may have a connection upward to the upper part of the tonsillar fossa. In order to obtain a satisfactory removal of one of these lesions, any connections which may be present must be removed at the time of operation. AnOlnalies Derived from the First Branchial Cleft
A cyst or sinus in the upper lateral neck appearing just below the midpoint of the mandible or possibly further back toward the angle of the jaw will usually be derived from abnormal failure of closure of the first branchial cleft. Cysts or sinuses in this position are less common
Fig. 533. Child with 2 fistulas derived from the second branchial cleft opening on the lower anterior sternocleidomastoid muscle. These fistulas extended up to the upper tonsillar fossa on each side, but tracts in this area do not necessarily extend all the way up.
than the anomalies of the second branchial cleft. The relative frequency of these lesions is only beginning to be recognized and pointed out. In a recent paper, Bill and Vadheim10 reported treating five remnants of the first cleft while treating 13 anomalies derived from the second cleft. The incidence has usually been reported much lower than this. As noted above, the first branchial cleft divides the area formed by the first branchial arch from that formed by the second branchial arch. Since the first arch forms the cheek and mandible and the anterior part of the external auricle, and since the first branchial cleft normally leaves the eustachian tube and the external auditory canal as its remnant, one would expect further remnants of the branchial cleft to extend from the
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n.
Fig. 534. Cyst and fistula derived from the first branchial cleft ending at the external auditory canal. (Reprinted from Annals of Surgery, by permission.)
Fig. 535. Child, aged 18 months, with fistula derived from first branchial cleft extending back and up to external auditory canal. (Reprinted from Annals of Surgery, by permission.)
external auditory canal downward and anterior to a point beneath the mandible. This was predicted by Frazer in 1926. 12 In those cases which have been described the tracts have been lined by skin components and have been surrounded by cartilage much like the structure of the external
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auditory canal (Figs. 534, 535). Experience seems to show that such a tract will pass lateral to the facial nerve as it approaches the external auditory canal. Technique of RerrlOval of Branchiogenic Cysts, Sinuses and Fistulas
While there is no set operation for the removal of these lesions as there is for the thyroglossal duct, yet the same principles must be followed. First of all, a transverse incision lying in the skin folds of the neck is always used. Secondly, we have found it helpful to inject the cysts or tracts with 3 to 4 cc. of a mixture of 5 parts hydrogen peroxide and 1 part methylene blue which will then travel along the tract as a result of the effervescence of the hydrogen peroxide. In the case of anomalies from the second branchial cleft it is well to remember that the lesion lies forward of the internal carotid and that its internal connection mayor may not extend all the way up to the superior aspect of the tonsillar fossa. Where the external opening of the fistula, or the cyst, is low and the tract is found to extend all the way upward, a second, higher, transverse incision will be helpful in the upper part of the dissection. In the case of a cyst or sinus appearing just beneath the posterior portion of the mandible the incision is again transverse and the dissection is carried out under direct vision so that there can be no possibility of injuring the facial nerve. Careless or blind dissection could result in such a catastrophe. The use of a small drain after removal of one of these tracts is sometimes helpful and depends upon the habits of the individual operator. SUMMARY
The course and possible connections of a cyst or sinus in the neck can be predicted by its location. A midline cyst or fistula may be expected to be a remnant of the thyroglossal duct and a connecting duct is likely to extend up through the substance of the hyoid bone to end at the foramen cecum at the back of the tongue. Removal of the entire tract is essentia.l for cure. A cyst or sinus presenting along the anterior border of the lower half of the sternocleidomastoid muscle may be expected to be a remnant of the second branchial cleft. Such a lesion may have a patent lumen ex:· tending up as far as the superior pole of the tonsil on the same side. The lumen, if present, must be excised for complete cure. A cyst or sinus appearing just beneath the posterior one-half of the mandible may be expected to derive from the first branchial cleft. Such a lesion will, as a rule, have a connection extending backward and up to the external auditory canal.
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REFERENCES 1. 2. 3. 4. 5. 6. 7. 8.
Thyroglossal Duct Anomalies Bailey, H.: Thyroglossal Cysts and Fistulae. Brit. J. Surg. 12: 579, 1925. Clute, H. M. and Cattell, R. B.: Thyroglossal Cysts. Ann. Surg. 92: 57, 1930. Gross, R. L. and Connerley, M. L.: Thyroglossal Cysts and Sinuses. New England J. Med. 223: 616-624, 1940. Norris, E. H.: The Early Morphogenesis of the Human Thyroid Gland. S. CLIN. NORTH AMERICA 9: 57, 1930. Pemberton, J. deJ. and Stalker, L. K.: Cysts, Sinuses and Fistulae of the Thyroglossal Duct. Ann. Surg. 111: 950-957,1940. Schlange, H.: Uber die Fistula colli congenita. Arch. f. klin. Chir. 46: 390, 1893. Sistrunk, W. E.: Surgical Treatment of Cysts of the Thyroglossal Tract. Ann. Surg. 71: 121, 1920. Stahl, W. M Jr. and Lyall, D.: Cervical Cysts and Fistulas of Thyroglossal Tract Origin. Ann. Surg. 139: 123, 1954. Branchiogenic Cleft Anomalies
9. Bailey, H.: The Clinical Aspects of Branchial Fistulae. Brit. J. Surg. 21: 173, 1933. 10. Bill, A. H. Jr. and Vadheim, J. L.: Cysts, Sinuses and Fistulas of the Neck Arising from the First and Second Branchial Clefts. Ann. Surg. 142: 904-908 (Nov.) 1955. 11. Byars, L. T. and Anderson, R.: Anomalies of the First Branchial Cleft. Surg., Gynec. & Obst. 93: 775, 1951. 12. Frazer, J. E.: The Disappearance of the Precervical Sinus. J. Anat. 61: 132-143, 1926. 13. Gross, R. E.: The Surgery of Infancy and Childhood. Philadelphia, W. B. Saunders Co., 1953. 14. Neel, H. B. and Pemberton, J.: Lateral Cervical (Branchial) Cysts and Fistulas. Surgery 18: 267-286, 1950. 15. Proctor, B.: Lateral Vestigial Cysts and Fistulas of the Neck. Laryngoscope 65: 355, 1955. 16. Rankow, R. M. and Hanford, J. M.: Congenital Anomalies of the First Branchial Cleft. Surg., Gynec. & Obst. 96: 103, 1953. 1008 Summit Avenue Seattle 4, Washington
one sees a child or an adult with a congenital cyst or sinus of the neck, one can ordinarily predict from the position of the lesion its relationship to other structures and what extensions may exist. A simple knowledge of the embryology of the neck is necessary for an understanding of these relationships and for the adequate surgical removal of such a cyst or sinus. WHEN
Fig. 525. Areas in which we expect to find remnants of the thyroglossal duct, the second branchial cleft, and the first branchial cleft.
As a rule, one can consider that the cysts or fistulas in the midline of the neck, from the level of the thyroid gland upward, are remnants of the thyroglossal duct. A cyst or sinus appearing in the lateral portion of the neck will, as a rule, be a remnant of incomplete closure of one of the branchial clefts, usually the second, but occasionally the first (Fig. 525).
* Attending Surgeon, Children's Orthopedic Hospital; Clinical Associate in Surgery, School of Medicine, University of Washington, SeatUe. 1599
1600
Alexander H. Bill, Jr. EMBRYOLOGY OF THE THYROGLOSSAL DUCT
Early in fetal life the major part of the thyroid gland, and indeed, some say all of the thyroid gland, starts is migration downward to its adult position from a point at the base of the tongue, known as the foramen cecum. The anlage of the gland migrates down in the midline of the neck anterior to the larynx and between the developing ends of the hyoid bone until its final resting place is reached. As the anlage descends, a tube from the base of the tongue is pulled down after it. This remains open until the gland reaches its normal level and then loses its lumen. It may occasionally remain open as a duct, in which case secretions from the cells lining it may flow back up into the mouth or, if the duct becomes plugged, will form a cystic swelling. Evidently the tube, or thyroglossal duct, remains open all the way up to the base of the tongue if it remains patent at all. This fact is of utmost importance if the surgeon is to remove a thyroglossal cyst completely, without the danger of recurrence. As noted above, the hyoid bone is formed from two halves which start their development from the sides and then fuse in the midline. The fusion of the bone transects the thyroglossal duct in such a way that the duct runs either directly through the substance of the bone or else lies closely applied to its upper or lower surface. Therefore when the thyroglossal duct remains patent, it is impossible to dissect out this part of it without removal of the center of the hyoid bone. While most of the cysts derived from the thyroglossal duct contain mucus, in a few cases the thyroid gland will not have completed its descent and the mass believed to be a cyst is actually the thyroid itself which has stopped somewhere along its course down to the lower neck. Recognition of this fact may at times prevent the removal of the entire thyroid gland. EMBRYOLOGY OF THE BRANCHIAL CLEFTS
As the fetus is forming, the sides of the neck present a series of folds. The prominence of the first fold, or "arch" as it is known, changes shape to form the structures of the cheek including the mandible and part of the external ear; while the second arch contributes to the external ear and then coalesces with the lower arches to form a smooth contour down the side of the neck. The folds between the arches are known as "branchial clefts." The first branchial cleft, which lies between the first and second arches, normally remains partly open to form the eustachian tube and the external auditory canal. The second branchial cleft, lying between the second and third arches, normally disappears. A glance at Figure 526 will show that the line of closure of the first branchial cleft will underlie a line extending from just below the center of the mandible back around the angle of the jaw and up to the external auditory canal. The base of the line of closure of the second branchial cleft will extend
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from a point on the lower anterior border of the sternocleidomastoid muscle slightly posteriorly and upward to end at the upper pole of the tonsillar fossa. The line of closure goes through the fork formed by the bifurcation of the internal and external carotid arteries. At times the depths of either the first or second cleft will not coalesce completely and
:'+.'-"--Carotid art
Fig. 526. Embryological derivation of lower face, ear and upper neck from the first and second branchial arches. The theoretical lines of closure of the first and second branchial clefts are shown in dotted lines. (Reprinted from Annals of Surgery, by permission.)
will therefore leave a tract. This may then either distend as a cyst, if there are no internal or external openings, or will drain either internally or externally, if there is such an opening. TREATMENT OF THYROGLOSSAL DUCT CYSTS AND FISTULAS
Any mass appearing in or near the midline of the neck, especially if it is cystic, and also if it appears to be infected, must be suspected of being a thyroglossal duct cyst. While the most usual place for such a cyst is in the midline between the level of the hyoid bone and the thyroid gland, reference to Figure 527 will show that these cysts can be found above this level. As one would expect from the embryology, the cysts do not usually communicate with the skin (Fig. 528). Occasionally, where there has been infection which has broken out to the surface, an epithelial-lined tract will become established between the cyst and the skin of the midline of the neck (Fig. 529). This, typically, will discharge purulent material or mucus.
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Lesions which may be confused with a thyroglossal duct cyst include dermoid cysts, which in comparison are relatively rare and often cannot be differentiated prior to operation. In the upper neck and in the submental region one may occasionally find a midline mass which proves to be a lymph node. As we have mentioned above, a solid mass may prove to be thyroid tissue which owes its presence in the upper neck to its incomplete descent. Most authorities recommend that a thyroglossal duct cyst be removed because sooner or later all, or certainly almost all, of these lesions become infected. This is understandable when one considers that thyroglossal
Fig. 527. Location in 22 cases of thyroglossal duct cysts or fistulas to show the relative frequency of location in the usual type of case.
duct cysts are connected by a patent duct with the back of the tongue and that infection may be introduced at any time through this avenue. Technique of Removal of Thyroglossal Duct Cyst or Sinus
A thyroglossal duct cyst or sinus should be removed at the early convenience of the patient and surgeon. If the lesion is, already infected, incision and drainage should be carried out and the infection allowed to subside. The operation which has been most consistently successful was evidently first suggested by Schlange 6 in 1893. To Sistrunk,7 however, must go the credit for the present day technique. The essential part of the technique, described by him in 1920, lies in the excision of the central
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1 or 2 cm. of the hyoid bone and then coring out a piece of tissue extending from the hyoid bone backward and upward to the base of the tongue at the foramen cecum.
Fig. 528. Child with infected thyroglossal duct cyst in the most frequently found position.
Fig. 529. Child with a draining thyroglossal duct fistula low in the neck.
The operation is performed with the patient under general anesthesia and with the neck extended (Fig. 530). A transverse incision is then made over the cyst or, if a fistula is present, a transverse ellipse of skin
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Fig. 530. Technique of removal of thyroglossal duct cyst or fistula. A, The incision should be transverse or transverse-elliptical. E, The cyst or fistula is dissected upward to the level of the hyoid bone. C, The hyoid bone is freed of its muscular attachments for 1 cm. on each side of the midline, and the bone is then cut on each side. D, With the hyoid still attached superiorly at its center, a 0.5 cm. core of tissue is removed up to the base of the tongue. This point is identified by the finger holding the base of the tongue forward and up toward the wound. The dissection is stopped at the whitish undersurface of the mucous membrane. The core of tissue will contain the upper portion of the thyroglossal duct.
is removed. The cyst or fistula is then dissected on all sides and its connection upward to the hyoid bone included in the dissection. This connection is as a rule fairly superficial and actually lies between the thyrohyoid muscles. When the dissection reaches the hyoid bone the muscular connections above and below the hyoid are cut in order to free the bone
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for a distance of about 1 cm. on either side of the midline. The attachments of the very center of the bone are left undisturbed since the duct is included in this tissue. An instrument is passed behind the hyoid on each side of the midline to free the bone in these areas. A cut is made through the bone about 1 cm. lateral to the center on each side, using small bone-cutting forceps. This, then, leaves the central 1 or 2 cm. of the bone freed from its lateral portions and attached in the middle of its posterior and superior aspects. With the freed central portion of the bone held in an instrument, a 0.5 cm. core of tissue is now dissected up toward the base of the tongue. This point can be identified by the forefinger of the anesthetist or of an assistant, which is placed at the base of the tongue and then pushes the tongue upward toward the wound. The dissection is stopped at the whitish membrane which indicates that the under side of the mucosal surface of the tongue has been reached. The core of tissue containing the upper portion of the duct is then cut off and the muscles of the tongue are reapproximated with a few interrupted sutures. The cut ends of the hyoid bone need not be approximated but the other muscle layers are closed with interrupted sutures. It has been our policy to leave a small drain up as far as the hyoid bone, and we have found that a rubber band serves very well for this purpose. The skin and subcutaneous tissues are closed around the drain in the usual manner, and a dressing is applied. The drain is removed in 24 hours. Pitfalls in the Operative Technique
While in the average case the technique described above is straightforward and without complications, yet the operator must be on the alert for variations in the course of the duct and for the possibility of thyroid tissue being present in place of a cyst. We have seen cases in which the cyst extended laterally from its midline position. In one instance this extended back to the side of the larynx. We have also seen cases in which the extension of the cyst appeared above the hyoid bone. These variations of anatomy must be anticipated and dealt with by accurate and careful dissection (Fig. 531). Possibly the most important pitfall is the assumption that there is no duct above the hyoid bone. This duct is often so small as to defy recognitionon dissection, yet the central portion of the hyoid bone and with it a core of tissue back to the tongue must be removed. As evidence of this we recently reviewed eight cases of thyroglossal duct cyst treated in a Seattle hospital several years ago. These cases had in common the fact that the center of the hyoid bone had not been removed. In seven of these eight cases recurrence had appeared within one year I The use of an up-and-down skin incision rather than a transverse one will always lead to a distressing scar that will contract and draw the normal contour of the neck out of shape. If the cyst or fistula is low in
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the neck, it may be difficult or impractical to remove the upper portion of the tract through the original transverse incision. In these circumstances a second transverse incision at the level of the hyoid bone will allow removal of the upper tract and yet will give a good cosmetic result. RECOGNITION AND TREATMENT OF BRANCHIOGENIC ANOMALIES
The differential diagnosis of a lateral mass· or a fistula in the neck is more difficult than when the mass is in the midline. If the mass can be shown to be cystic, it is most likely to be a cyst derived from one of the
"liMtFig. 531. Variations in position or pathology in 4 unusual cases of thyroglossal duct anomaly. a, Cyst presenting in submental region and under tongue. b, Mass proved to be thyroid tissue just anterior to hyoid bone. c, Thyroglossal duct cyst with a lateral extension going around to side of larynx. d, Unusual course of duct.
branchial clefts. In a child, however, it could possibly be a cystic hygroma. Such a mass will be multilocular as a rul~, which will serve to make the diagnosis at operation. Another large group of lateral masses in the neck include inflammatory or neoplastic enlargements of the lymph nodes. The history is often of some help in arriving at the diagnosis of a cyst since many of these will have been present for a long time with no evidence of inflammation. Inflammation may, of course, be superimposed. Likewise, a branchiogenic sinus or fistula may be difficult to differentiate from one with an inflammatory origin. Again the history
1 j
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may help since a congenital branchiogenic sinus or fistula will most likely have been present since birth, with seepage of mucus from the opening ever since the parents can remember. In any of these lesions tuberculosis needs to be considered and ruled out. AnOInalies of the Second Branchial Cleft
A cystic mass or a sinus presenting along the anterior border of the sternocleidomastoid muscle in the lower half of the neck will, in general, represent a remnant of the second branchial cleft. Reference to Figure 532 will show the possible abnormalities with either a sinus-like opening or a cyst. The base of the second branchial cleft appears to leave remnants in the same manner that a hernial sac or a hydrocele are remnants of the processus vaginalis. By this we mean that an isolated portion of
Cyst with pharyngeal openinq Extel"nal sinus
Fig. 532. Schematic outline of possible anomalies derived from the second branchial cleft. (Modified and reprinted from Annals of Surgery, by permission.)
the base of the cleft may stay open as a cyst, or that one end may stay open for varying distances as a sinus, or, finally, that the entire base of the cleft may remain patent as a fistula from the upper tonsillar fossa to the lower neck. The remnants of the second branchial cleft differ from those of the thyroglossal duct to the extent that the internal, or upper, end of the branchial cleft remnant does not always have a lumen. If the upper extension of the tract stays open, it will pass upward through the bifurcation of the internal end of the common carotid arteries. If a sinus tract presents itself on the anterior border of the lower portion of the sternocleidomastoid muscle, this tract may extend only for a centimeter or two, or it may extend all the way up to the upper tonsillar fossa on the same side (Fig. 533). Similarly, a cystic mass presenting just
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Alexander H. Bill, Jr.
anterior to the sternocleidomastoid muscle along its lower or middle third may be a blind cyst, or it may have a connection upward to the upper part of the tonsillar fossa. In order to obtain a satisfactory removal of one of these lesions, any connections which may be present must be removed at the time of operation. AnOlnalies Derived from the First Branchial Cleft
A cyst or sinus in the upper lateral neck appearing just below the midpoint of the mandible or possibly further back toward the angle of the jaw will usually be derived from abnormal failure of closure of the first branchial cleft. Cysts or sinuses in this position are less common
Fig. 533. Child with 2 fistulas derived from the second branchial cleft opening on the lower anterior sternocleidomastoid muscle. These fistulas extended up to the upper tonsillar fossa on each side, but tracts in this area do not necessarily extend all the way up.
than the anomalies of the second branchial cleft. The relative frequency of these lesions is only beginning to be recognized and pointed out. In a recent paper, Bill and Vadheim10 reported treating five remnants of the first cleft while treating 13 anomalies derived from the second cleft. The incidence has usually been reported much lower than this. As noted above, the first branchial cleft divides the area formed by the first branchial arch from that formed by the second branchial arch. Since the first arch forms the cheek and mandible and the anterior part of the external auricle, and since the first branchial cleft normally leaves the eustachian tube and the external auditory canal as its remnant, one would expect further remnants of the branchial cleft to extend from the
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n.
Fig. 534. Cyst and fistula derived from the first branchial cleft ending at the external auditory canal. (Reprinted from Annals of Surgery, by permission.)
Fig. 535. Child, aged 18 months, with fistula derived from first branchial cleft extending back and up to external auditory canal. (Reprinted from Annals of Surgery, by permission.)
external auditory canal downward and anterior to a point beneath the mandible. This was predicted by Frazer in 1926. 12 In those cases which have been described the tracts have been lined by skin components and have been surrounded by cartilage much like the structure of the external
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auditory canal (Figs. 534, 535). Experience seems to show that such a tract will pass lateral to the facial nerve as it approaches the external auditory canal. Technique of RerrlOval of Branchiogenic Cysts, Sinuses and Fistulas
While there is no set operation for the removal of these lesions as there is for the thyroglossal duct, yet the same principles must be followed. First of all, a transverse incision lying in the skin folds of the neck is always used. Secondly, we have found it helpful to inject the cysts or tracts with 3 to 4 cc. of a mixture of 5 parts hydrogen peroxide and 1 part methylene blue which will then travel along the tract as a result of the effervescence of the hydrogen peroxide. In the case of anomalies from the second branchial cleft it is well to remember that the lesion lies forward of the internal carotid and that its internal connection mayor may not extend all the way up to the superior aspect of the tonsillar fossa. Where the external opening of the fistula, or the cyst, is low and the tract is found to extend all the way upward, a second, higher, transverse incision will be helpful in the upper part of the dissection. In the case of a cyst or sinus appearing just beneath the posterior portion of the mandible the incision is again transverse and the dissection is carried out under direct vision so that there can be no possibility of injuring the facial nerve. Careless or blind dissection could result in such a catastrophe. The use of a small drain after removal of one of these tracts is sometimes helpful and depends upon the habits of the individual operator. SUMMARY
The course and possible connections of a cyst or sinus in the neck can be predicted by its location. A midline cyst or fistula may be expected to be a remnant of the thyroglossal duct and a connecting duct is likely to extend up through the substance of the hyoid bone to end at the foramen cecum at the back of the tongue. Removal of the entire tract is essentia.l for cure. A cyst or sinus presenting along the anterior border of the lower half of the sternocleidomastoid muscle may be expected to be a remnant of the second branchial cleft. Such a lesion may have a patent lumen ex:· tending up as far as the superior pole of the tonsil on the same side. The lumen, if present, must be excised for complete cure. A cyst or sinus appearing just beneath the posterior one-half of the mandible may be expected to derive from the first branchial cleft. Such a lesion will, as a rule, have a connection extending backward and up to the external auditory canal.
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REFERENCES 1. 2. 3. 4. 5. 6. 7. 8.
Thyroglossal Duct Anomalies Bailey, H.: Thyroglossal Cysts and Fistulae. Brit. J. Surg. 12: 579, 1925. Clute, H. M. and Cattell, R. B.: Thyroglossal Cysts. Ann. Surg. 92: 57, 1930. Gross, R. L. and Connerley, M. L.: Thyroglossal Cysts and Sinuses. New England J. Med. 223: 616-624, 1940. Norris, E. H.: The Early Morphogenesis of the Human Thyroid Gland. S. CLIN. NORTH AMERICA 9: 57, 1930. Pemberton, J. deJ. and Stalker, L. K.: Cysts, Sinuses and Fistulae of the Thyroglossal Duct. Ann. Surg. 111: 950-957,1940. Schlange, H.: Uber die Fistula colli congenita. Arch. f. klin. Chir. 46: 390, 1893. Sistrunk, W. E.: Surgical Treatment of Cysts of the Thyroglossal Tract. Ann. Surg. 71: 121, 1920. Stahl, W. M Jr. and Lyall, D.: Cervical Cysts and Fistulas of Thyroglossal Tract Origin. Ann. Surg. 139: 123, 1954. Branchiogenic Cleft Anomalies
9. Bailey, H.: The Clinical Aspects of Branchial Fistulae. Brit. J. Surg. 21: 173, 1933. 10. Bill, A. H. Jr. and Vadheim, J. L.: Cysts, Sinuses and Fistulas of the Neck Arising from the First and Second Branchial Clefts. Ann. Surg. 142: 904-908 (Nov.) 1955. 11. Byars, L. T. and Anderson, R.: Anomalies of the First Branchial Cleft. Surg., Gynec. & Obst. 93: 775, 1951. 12. Frazer, J. E.: The Disappearance of the Precervical Sinus. J. Anat. 61: 132-143, 1926. 13. Gross, R. E.: The Surgery of Infancy and Childhood. Philadelphia, W. B. Saunders Co., 1953. 14. Neel, H. B. and Pemberton, J.: Lateral Cervical (Branchial) Cysts and Fistulas. Surgery 18: 267-286, 1950. 15. Proctor, B.: Lateral Vestigial Cysts and Fistulas of the Neck. Laryngoscope 65: 355, 1955. 16. Rankow, R. M. and Hanford, J. M.: Congenital Anomalies of the First Branchial Cleft. Surg., Gynec. & Obst. 96: 103, 1953. 1008 Summit Avenue Seattle 4, Washington