thyroglossal cyst disease treatment management complication pathology physiology final year mbbs surgery seminar presentation tdmc kerala

1. z
THYROGLOSSAL
DUCT CYST
SARATH TK
116 BATCH
ROLL NO 87

2. z
Case scenario
 A 10 year old girl presents with spherical, swelling in
midline of front of neck for the past two years.
 History of presenting illness: Swelling was of insidious
onset and gradually increased in size. No history of pain
over swelling or discharge from swelling.

3. z
 On Examination: Site- Midline of front of neck, just beneath the
hyoid
Size and shape- 1.5 cm diameter round swelling
Surface- smooth
Margins- rounded, free from underlying skin and structures
Fluctuation- negative
Trans illumination- negative

4. z
 The swelling moved with deglutition and with protrusion of
tongue
 Regional lymph nodes were not enlarged
 thyroid appears normal with no ectopic tissue
 Examination of oral cavity and tongue: no lingual thyroid
PROBABLE DIAGNOSIS: Thyroglossal cyst, possibly sub hyoid

5. z
Differential diagnosis
 Thyroid nodule
 Dermoid cyst
 Infected/ enlarged lymph node, Collar stud abscess
 Lipoma
 Sebaceous cyst
 Subhyoid bursitis

6. z
Anatomy and Embryology
 Thyroid gland develops from a median down growth of a column of cells from the
pharyngeal floor between 1st and 2nd pharyngeal pouches
 This canalised column becomes the thyroglossal duct(extends from Foramen
caecum of tongue to isthmus of thyroid gland)
 Which is later displaced by the developing hyoid bone
 Parafollicular c cells arise from neural crest through ultimobranchial body

7. z

8. z
Fate of thyroglossal duct:
Lower part- Isthmus, lateral lobes of thyroid
Part from Foramen caecum to Isthmus- disappears by 5-10 weeks
of development
Sometimes, part from hyoid to isthmus persists- Levator glandulae
thyroidae

9. z
 Along the course of the duct- ectopic thyroid tissue may form
 Some times a part of thyroglossal duct may remain
unobliterated and there would be accumulation of secretion
leading to formation of thyroglossal cyst
 Duct usually descends in front of the hyoid bone, sometimes
forms a retro hyoid loop and then descends downwards and
rarely the duct may pass through the hyoid bone

10. z
Thyroglossal cyst
 Thyroglossal cyst is a swelling occurring in the neck in any
part along the persisting thyroglossal tract.
 It occurs if the thyroglossal duct fails to obliterate completely 
forms cystic swelling with mucus filling
 Normal thyroid maybe in normal site(fossa) , but occasionally it
may be in walls of the thyroglossal cyst.
 it is a Tubulodermoid type of cyst
 Cyst is lined by pseudostratified ciliated columnar epithelium

11. z
INCIDENCE
 Accounts for 70% of all congenital neck anomalies
 And duct cysts are present in about 7% of the population worldwide
 They have an equal preponderance between male and female individuals
 Commonly diagnosed in preschool and adolescents age group

12. z
POSSIBLE SITES
 Subhyoid (most common 65%)
 Level of thyroid cartilage (2nd most common site)
 Suprahyoid
 Beneath the foramen caecum
 Floor of mouth

14. z
Clinical features
 Swelling in midline but, when they are adjacent to the thyroid cartilage,
they may lie slightly to one side of the midline
 Smooth, soft, fluctuant if large, non tender, mobile and often times
transilluminant.
 Swelling moves with deglutition and also with protrusion of tongue.
Method: Patient is asked to open the mouth and keep lower jaw still. Hold
the cyst between thumb and index finger. When patient is asked to
protrude the tongue, a tugging sensation is felt.

18. z
Complications
 Inflammation and increase in size due to upper respiratory
tract infections
 Thyroglossal cyst can get infected and may form an abscess
 Further infections are common because the cyst wall
contains lymphatic tissue
 Discharging sinus, Thyroglossal fistula
 Papillary carcinoma thyroid- 1%

19. Infected thyroglossal cyst

20. z
Investigations
 Radioisotope study- technetium 99m pertechnetate scan
 Ultrasonography- nature of thyroid nodule, cystic component of mass
 FNAC of cyst
 T3,T4, TSH estimation

21. CT scan showing cystic swelling
in midline of neck

22. z
Treatment
 Antibiotics to control infection
 Sistrunk operation:
Excision of whole thyroglossal tract including body of hyoid,
suprahyoid tract through tongue base to the vallecula at the
sides of foramen caecum, together with a core of tissue on
either side

23. z
TECHNIQUE
Transverse neck incision
over cyst
Platysma also raised with
skin flap(Don’t open the
cyst)
Cyst and surrounding
tissue dissected upto
hyoid
Strap muscles
(sternohyoid and
thyrohyoid) are divided
Central part of hyoid of 1
cm width removed along
with intact tract
Geniohyoid and
mylohyoid muscles also
divided
Track with tissues
dissected upto foramen
caecum
Assistant can digitally
apply pressure over
tongue base for proper
dissection
Track ligated at foramen
caecum and removed

24. z
 Adjacent tissues removed because of possibility of multiple tracks.
 Complications:
 Recurrence(If hyoid not removed: 25%; Completely removed: 5%)
 Thyroglossal fistula (if tract not completely removed)
 Hemorrhage/hematoma
 Infection

25. z
 Low lying cyst may need two parallel incisions above and
below hyoid to remove whole tract
 Recurrent disease- more aggressive Koempel’s suprahyoid
technique is done
 Others: En bloc central neck dissection; Suture guided
transhyoid pharyngotomy

27. z
Thyroglossal Fistula
 Usually acquired from: Bursting of cyst
Incision of inflamed cyst
Local removal of cyst without tract excision
 Midline fistula- rarely a true fistula, usually a discharging sinus
 Lined by columnar epithelium, discharges mucus
 Has recurrent infections

28. z
 Usual site: Just below hyoid bone
 In infants, tend to be lower
 D/D: Tuberculous sinus

29. Thyroglossal fistula with
indrawn opening

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Features:
 Hood sign- Opening of fistula indrawn and overlaid by a fold of
skin
 Semilunar sign- Crescentic appearance
 Investigations: Radio isotope study and Fistulogram
 Treatment: Sistrunk operation

32. z
Malignant change
-Cyst is hard , irregular & fixed with palpable neck nodes. Rapidly increasing
in size
-Confirmed on biopsy after excision
 Indications for complete thyroidectomy:
1) Nodular thyroid with Cold nodule
2) Enlarged neck nodes
3) History of neck irradiation

33. z
 Usually done- Sistrunk operation if thyroid is normal
 Following thyroidectomy, Radio iodine ablation is recommended
irrespective of thyroid status.
 Long term follow up necessary.

34. z
Thank you