i yo 



APPLIED ANATOMY. 



in itself does not form pathological fistulae, but congenital fistulae are sometimes 

 encountered in the external ear which are the remains of the clefts between the 

 tubercles of which the ear is formed. 



Cervical fistulae or sinuses may extend either completely through, from the 

 surface to the pharynx, or may open internally or externally, or be closed at both 

 ends, in which last case the contents accumulate and form a cervical cyst. 



Fistula arising from the second visceral cleft open externally opposite the thyro- 

 hyoid space in front of the sternomastoid muscle. Internally they open into the 

 recess holding the tonsil. 



Fistula arising from the third and fourth visceral clefts open externally lower 

 down nearer the sternoclavicular articulation in front of the sternomastoid muscle and 



internally in the sinus pyriformis. The 

 persistence of the third and fourth 

 visceral clefts internally may produce 

 pharyngeal diverticula, as already 

 noted in discussing that region. 



In attempting the cure of cysts 

 and fistulas due to persistence of the 



Thyroglossal duct 



Median cervical 

 pouch or cyst 



FIG. 190. Median cervical pouch or cyst arising from the FIG. 191. Median cervical (thyroglossal) 



thyroglossal duct. Marshall's case. cyst. Author's case. 



visceral clefts it is evident that as they are lined with a secreting epithelium this must 

 be destroyed or removed, or a recurrence will take place. In attempting to dissect 

 them out one must be prepared to follow them through the structures of the neck 

 to the pharynx inside. It is needless to say this may be a serious procedure. 



Hueter (quoted by Sutton) followed one between the two carotid arteries into the 

 pharynx. These cysts and fistulae may be noted at birth or may develop later in life. 



Hydrocele of the Neck. There are other cystic tumors of the neck which 

 are congenital, being noticed at birth, and which grow to a large size. They are 

 often wide-spread, extending not only between the tissues of the neck below the 

 deep fascia but even into the axilla. Their walls are thin, consisting sometimes only 

 of a layer of lining epithelium and the surrounding tissues. On this account it is 

 impossible to dissect them out. The use of injections and setons has been aban- 

 doned as too dangerous. They rarely require treatment, as they tend to disappear 

 spontaneously. Mr. J. Bland Sutton ascribes their origin first to congenitally dilated 

 lymph-spaces; second as resembling the cervical air-sacs that exist in the howling 

 monkeys; and third that possibly some of them may be related to a persistence of 

 some portion of a branchial cleft. 



Median cervical fistulae and cysts originate in connection with the thyro- 

 glossal duct. This, in the embryo, leads from the foramen caecum at the root of the 



