----------------------------------------------------------------------------- TITLE: Congenital Cysts and Sinuses SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: October 1991 RESIDENT PHYSICIAN: Mark L. Nichols, M.D. FACULTY: Karen H. Calhoun, M.D. DATABASE ADMINISTRATOR: Melinda McCracken, M.S. ----------------------------------------------------------------------------- "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." Congenital Cysts and Sinuses I. General A. branchial (pharyngeal) apparatus appears at approximately 4th week of intro-uterine life. B. basically a gill slit type of development at this time with 5 pairs of mesodermal arches separated by 4 pairs of grooves or clefts externally and pouches internally. C. arches develop into mesoderm derivatives (muscle, bone, vessels, cartilage). D. pouches develop into entoderm derivatives. E. grooves develop into ectoderm derivatives. F. pouches become glandular structures and in the process their connection to the ectoderm of the groove obliterates and remnants of this connection become branchial sinuses and cysts. G. each arch is associated with an artery, nerve, and cartilage bar. and muscle component. The nerves are anterior to the arteries except in the fifth arch, where it is posterior. Caudal to all arches is the XIIth nerve. The sternocleidomastoid muscle is derived from cervical somites posterior and inferior to the above arches. H. are 2 ventral and 2 dorsal aortas in early embryonic life. The 2 ventral fuse completely while the 2 dorsal fuse caudally only. II. Specific A. First Arch 1. Involved with development of the face. 2. Small hillocks or elevations develop from the dorsal ends of the 1st and 2nd arches surrounding the 1st groove fuse to form the external ear. -1st arch:1st hillock ---> tragus 2nd hillock ---> helical crus 3rd hillock ---> helix -2nd arch:4th hillock ---> antihelix 5th hillock ---> antitragus 6th hillock ---> lobule and lower helix 3. Arch (cartilage bar known as Meckel's). -mandible; head, neck and manubrium of malleus; body and short process of incus, anterior malleal and sphenomandibular ligament, tensor tympani, muscles of mastication, anterior belly of digastric, tensor palatini muscle. 4. Nerve is the trigeminal. 5. Artery degenerates. 6. Pouch forms the middle ear cavity and port of the palatine tonsil and tonsillar fossae. B. Second Arch 1. Arch (cartilage bar known as Reichert's) -cartilage forms manubrium of malleus, long process of incus and lenticular process, stapes (except vestibular portion and annular ligament), Styloid process, pyramidal eminence, stylohyoid ligament, lesser cornu of hyoid, part of body of hyoid, lower half of facial canal. -mesoderm forms platysma, stapedius muscle, and tendon, facial m., auricular m., buccinator m. -Nerve is the facial N. -Artery is the stapedius which usually degenerates. -Pouch forms part of the tonsil fossae and palatine tonsil along with parathyroid three. During development, the thymus will descend caudally pulling parathyroid 3 with it, thus parathyroid 3 will ultimately rest inferior to parathyroid 4. C. Third Arch 1. Arch forms greater cornu of hyoid, and part of the body along with the stylopharyngeus m. 2. Nerve is the glossopharyngeal. 3. Artery is the precursor of the carotid artery on both sides. 4. Pouch forms the thymus and parathyroid 4. D. Fourth Arch 1. Arch forms the thyroid cartilage, cuneiform cartilage. -mesoderm forms the inferior constrictor m., cricothyroid m., cricopharyngeus m. 2. Nerve is the superior laryngeal N. 3. The left 4th arch artery becomes the arch of the aorta. The right 4th arch artery becomes the proximal subclavian. -should the right fourth arch artery degenerate and the right subclavian arise from the dorsal aorta, the subclavian would now be posterior to the esophagus. This can cause a constriction and "dysphagia lusoria." 4. Pouch is the ultimobranchial body whose fate is unknown. E. Fifth Arch 1. Cartilage bar forms the cricoid, arytenoid, and corniculate. -mesoderm forms the intrinsic muscles of the larynx (except the cricothyroid) and the trachea. 2. Nerve is the recurrent laryngeal. -this nerve is posterior and caudal to the artery. On the right, the artery degenerates and the nerve will loop around the subclavian. (4 arch vessel). On the left, will loop around the aorta and ductus arteriosus. 3. Left 5th arch artery becomes the pulmonary artery and ductus arteriosus. The right 5th arch artery becomes the pulmonary with degeneration of the rest of this arch vessel. III. Congenital Malformations of the Arches A. Preauricular pits (sinuses, skin tags) 1. Arise from failure of fusion of the auricular hillocks around the dorsum of 1st & 2nd branchial arch. 2. Occur anterior to the pinna, and although they may arborize, they are not related to the EAC. 3. Always lateral to the facial nerve. 4. Treatment is surgical excision. B. Cysts & Sinuses 1. Branchial Cleft Cysts -male = female -smooth, round, nontender mass along anterior border, and deep to the SCM at any position between the EAC and clavicle. -usually not recognized until 2nd decade of life owing to their size and slow accumulation of fluid. 2. Branchial Sinus development -female greater male -often palpable as fibrous cord along anterior border of SCM. -usually recognized in infancy due to external opening. 3. Histopathology -Generally lined by stratified squamous epithelium that often contains keratin, hair follicles, sweat and sebaceous glands. -8 - 10% have ciliated columnar epithelium -organized lymphocyte infiltrate with germinal contents often seen in their walls. 4. 1st Cleft Defects (2 types) -relatively uncommon (about 1% of clefts) -work proposed 2 classes -Type I extremely rare -clinically a cystic mass of fistula posterior to the pinna or concha. -usually superior to the main trunk of the fascial nerve and ends in a cul-de- sac on or near a bony plate at the level of the mesotympanum. -basically are purely an ectodermal defect, on duplication anomaly of the membranous EAC. -Type II -represent a duplication anomaly of both membranes and cartilaginous portion of the EAC. (ectodermal and mesodermal). -associated most frequently with fistulae in the conchae or EAC as well as in the neck; sinus tract usually extends medial, inferior, and anterior to the EAC and may extend deep to the facial nerve or even intertwine with the pes. -Frequently a fistula below the angle of the mandible at the anterior border of the SCM. -Belerky and Medina have proposed a revision of Work's classification. Their scheme based on anatomy and not histology. -Type I is a cyst or sinus or fistulous tract in the preauricular region and the tract courses lateral and superior to the facial nerve, parallels the EAC and terminated without an opening in the canal. -Type II is below the mandible in the anteriosuperior neck. Tract courses superiorly over ramus of mandible and terminates at the bony cartilaginous junction at the EAC, either with or without direct communication. -Tip off is a persistently draining ear in the absence of middle ear disease with a draining sinus or abscess in the neck. 5. Second Cleft Defects (most common). -cysts are more common than fistulas or sinuses -external opening, if present, is located along the anterior border of the SCM at the junction of the lower and middle third. -The fistula, if present, is subplatysmal ascends along the carotid sheath and crosses over the hypoglossal N. and glossopharyngeal N. (3rd arch). It then passes between the internal and external carotid arteries and ends at the tonsil or fossae where an internal os may be present. -cysts may occur anywhere along the course of the fistula but are much more common in the anterior triangle. -rare complication is fistula with jugular vein. 6. Third Cleft Defects (rare) -external ostium may be located at the same place as 2nd cleft if present. -Fistula tract, if present, will be superficial to XII ascending along the carotid sheath behind the internal carotid artery (3rd arch), and pass under the glossopharyngeal N. but superficial to the vagus N. It will pass through the thyrohyoid membrane above the internal branch of the superior laryngeal nerve and open into the pyriform fossae. 7. Fourth Cleft Defect -theoretically possible, but never demonstrated in their entirety. -Epithelial cysts in mediastinum have been described and could possible represent a branchial remnant. -external opening would be along border of SCM anteriorly lower in neck. -On the right, the tract would loop around the subclavian and rise deep to carotid, lateral to XII and then descend to open into the esophagus, lower part of pyriform or larynx. The left would pass under the arch of the aorta or ligamentum arteriosus medially. 8. Treatment -Only definitive treatment is surgical excision. -often present initially with infection; incidence of second infection greater than 25% with excision. -indications for excision may include recurrent infection, undesirable cosmetic appearance, rare possibility of malignant degeneration and venous fistula. -radiation, injection of sclerosing agents, repeated I&D associated with high recurrence rate and increase risk of infection, hemorrhage, disfigurement. 9. Preoperative -search for bilateral lesions (about 2%) -search for other congenital defects -treat infection first and delay surgery until subsides, usually about 6 weeks -usually gm(+); strep and staph -in infant, delay surgery until at least 24 months old; this will decrease anesthetic risk and allow easier operation technically. -Radiopaque injection helpful to trace path of tract, especially with type I. 10. Procedure (Principles) -always excise ellipse of skin around sinus -incise along langner's lines over nose -follow tract -for tract low in neck helpful to use horizontal "stepladder" incision -incision along ant border of SCM also permissible but leaves less cosmetic scar -lacrimal probes may help follow tract -also may use methylene blue to help follow tracts, mainly with Type I -with 1st branchial cleft cysts, may need to perform superficial parotidectomy to remove; may interweave with facial N. -Careful excise all of tract and continue until either ends in a fibrous bend or enters pharynx. 11. Recurrence -2X greater with sinus than cyst -varies from 3% (without prior surgery or infection) to 20% 12. Differential -Bronchogenic carcinoma -a SCCA thought to arise in a branchial cleft remnant, used in part to explain a cancer in lateral neck without obvious primary. -existence of this entity open to question. -wide local excision with RND after occult 1st degree ruled out. -TB adenitis -often multiple draining fistulas from central necrotic nodes. -lipoma -in subcutaneous tissue, above platysma -not fluctuant and does not fistulize -cervical metastasis form head and neck CA -cystic hygroma -usually presents a birth -carotid body tumor -mobile laterally, but not vertically -angiogram -lymphoma -more systemic symptoms -hemangioma ->90% seen in first year of life cavernous type called "bag of worms" -Boiley's sign- compress mass and blood moves out and the mass decreases in size. -most will involute by the first few years of life and just need watchful waiting. -may embolize the cavernous types -Endocrine cysts--> TDC, thymic cysts -thymic mass low in the neck, uncommon, usually around the supraclavicular region. -will decrease with inspiration; this is characteristic -CXR shows smooth density or mass filling the anterior mediastinum. -Parathyroid adenoma -Parotid lesions -chronic retropharyngeal abscess -neurofibroma -fibromatosis coli-torticollis -mass in SCM of the newborn at about 10 days after birth. -may enlarge over several weeks and resolve over 8-10 months. -FNA helpful if continues to enlarge after several weeks. -dermoids occasionally or submental mass or midline cervical mass. -teratomas, usually more lateral in the neck. IV. Thyroglossal Duct Anomalies A. In four week old embryo a ventral (thyroid) diverticulum is of endodermal origin can be identified between the first and second arches on the floor of the pharynx. This site later becomes the foramen cecum. It descends caudally within mesodermal tissues giving off the primordial structures that will become the thyroid gland. By 4 1/2 weeks the connection between the diverticulum and floor of the pharynx begins to disappears and should be obliterated i at six weeks. This duct travels through the hyoid to reach the foramen cecum. If the duct persists a thyroglossal duct cyst is present. -Duct remnants can be found anywhere along the line of descent; 2/3 midline directly inferior to the hyoid, but may be submental, suprasternal,or mediastinal. B. Histology -may be lined with squamous, ciliated, columnar or transitional epithelium. -may be surrounded with fibrous tissue, with an inflammatory cell infiltrate, but without organized lymphoid tissue. -cyst fluid mucinous, often with cholesterol crystals; may be mucopurulent. -subepithelial islands of thyroid tissue may confirm disease. -carcinoma arising in duct remnant is extremely rare, but may be found at any age. Usually discovered incidentally on cyst removal and is usually papillary adenocarcinoma in the majority. B. Clinical Presentation -80% appear as painless, asymptomatic mass near or in the midline of the neck between the hyoid bone and thyroid cartilage. -50% present at < 10 years old, 65% before age 20. -may first be noticed with URI or acute infection -Protrusion of the tongue will elevate cyst since it is attached to the foramen cecum. C. Preoperative Evaluation -FNA will help confirm diagnosis -CT scan is not usually performed, but will show high density mass. -ultrasound not usually performed, but will differentiate cystic vs. solid. -FNA gives this information -radionuclear thyroid scan -controversial -argument against is that the presence of a thyroglossal duct remnant has implied that the gland has descended. Total incomplete descent is very rare. -may be mistaken for aberrant thyroid and these patients may be hypothyroid. Removal of tissue may precipitate myxedema. Argument for is if aberrant thyroid located, get TFT's and correct state prior to surgery. Same applies for lingual thyroid. D. Surgery -consists of excision of complete cyst and tract after any acute infection is resolved. Sistrunk procedure employed which involves removal of central portion of hyoid bone and carried down in a cone shaped piece of tissue to the foramen cecum. Taking hyoid has marked decrease in rate of recurrence from about 50% to less than 20%. Once care of the tissue removed also to tongue, rate dropped to less than 5%. -------------------------------------------------------------------------- BIBLIOGRAPHY 1. Finn, Douglas, et al; Branchial Cleft Cysts: Clinical Update, Laryngoscope 97; Feb 1987; pp.136-140. 2. Rood, S., et al; Diagnosis and Management of Congenital Head and Neck Masses, SIPAC by AAO-HNS; 1981; pp.12-43. 3. Lee, K. J.; Essential Otolaryngology, Medical Examination Publishing Co.; 1983; pp.292-312. 4. Roseman, J.; et al; Branchial Cleft Cyst to Jugular Vein Fistula, Archives of Otolaryngology- Head and Neck Surgery; Vol. 110, No. 10; Oct. 1984; pp.688-689. 5. Johnson, C., et al; Congenital Neck Masses in Current Therapy of Otolaryngology- Head and Neck Surgery, B. C. Decker, Inc.; 1987; pp.218-220. 6. Dovies, J.; Embryology of the Head and Neck in Relation to the Practice of Otolaryngology, SIPAC by AAO-HNS; 1980; pp.5-22. 7. Albess, G. D.; Congenital Sinuses and Fistulas of the Neck and Pharynx, English- Otolaryngology, Harpe and Row Publishers; Vol. 3, Chapter 12. ----------------------------------END-------------------------------------