Thyroglossal Cyst

45 year gentleman, from non-endemic zone for goitre with-

·         Painless swelling midline neck-15 years

·         Gradually increasing in size- 6 months

·         No constitutional features

·         No history suggestive of local compression/ infiltration/ distance metastasis

·         No history suggestive of hypo/hyperthyroidism

Local examination-

·         Single swelling in midline of neck just above thyroid cartilage

·         Size (4*4cm)

·         Move with protrusion of tongue {how to examine – patient neck extended, mouth remain opened during whole period of this examination, patient is asked to protrude the tongue or deglutinate, note for movement of swelling , reason for keeping the patient neck in extended position- impair the mobility in flexed posture, it would not be clearly seen in flexed posture, thyroglossal tract will become coiled in flexed posture}

·         Inspection-

o   Surface- smooth

o   Margins are well defined

o   Skin overlying swelling- normal

o   On skin there is a mark of needle aspiration

o   No regional lymphadenopathy

o   Rest of head and neck and cervical spine examination was normal

·         Why Transillumination test is usually negative in thyroid swelling?

o   It is because of content-CHOLESTEROL CRYSTALS

·         Any swelling which arise from thyroid or pretracheal fasciae will move with deglutition  Eg- thyroid, pretracheal lymphnodes, subhyoid bursae, laryngocele,

·         Pre tracheal lymphnodes, subhyoid bursae, laryngocele – not move with protrusion of tongue

·          Provisional diagnosis in this case- Thyroglossal cyst

Approach to the patient-

Only swelling moving with protrusion of tongue- thyroglossal cyst

·         If thyroglossal tract does not operated - what will happen?- infection (arising from oral cavity, Waldeyers ring, haematogenous), haemorrhage, torsion, malignancy(papillary).

Investigation –

·         Confirm the diagnosis-

o   USG Thyroid {where is the cyst, where it lies, thyroid gland status}.  

o   USG guided FNAC if malignancy suspected (FNAC not to be done for simply diagnosing the case because there is chance of introducing infection)

o   Thyroid function test

·         Support the diagnosis –

·         To treat the patient - 

Informed consent- include there may be change in voice (superior laryngeal is more close to thyroid- pitch and timber of voice will be affected)

Surgery:-

·         Surgery- Sistrunk operation {excision of cyst, resection of body of hyoid bone, excision of thyroglossal tract- go the the base of mylohoid muscle and ask the anaesthetist to push the tongue down, level VI lymph node will be involved}

·         Incision-  incision should be higher up than normal thyroid incision and should be in the crease.

·         Why higher up incision?-  1. cyst is higher up 2. Hyoid bone  excision.

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