1. Lingual thyroid is a rare condition where the thyroid gland is located at the base of the tongue instead of the normal location in the neck. Investigations like thyroid scan and CT neck can help locate the gland. Treatment involves medical therapy initially and surgery if medical treatment fails. 2. Thyroglossal cysts arise from remnants of the thyroglossal duct during embryonic development of the thyroid gland. Sistrunk operation is the treatment of choice which involves removal of the cyst along with a portion of the hyoid bone and any connecting tract. 3. A cold nodule seen on a thyroid scan could indicate a benign cyst, colloid nodule, or follicular carcinoma of the thyroid

1. THYROID GLAND

2. C/P : tongue swelling impaired speech dyshpagia respiratory obestruction A- lingual thyroid INVESTIGATIONS : thyroid scan C.T. neck lateral view showing Lingual thyroid TTT. : IF only thyroid tissue medical ttt. & if failed surgical excision

4. Thyroglossal cyst & fistula INDEX

5. INDEX The classical site for a thyroglossal cyst Thyroglossal cysts Embryology The thyroglossal tract arises form foramen caecum at junction of anterior 2/3 and posterior 1/3 of the tongue. Any part of the tract can persist causing a sinus, fistulae or cyst. Most fistulae are acquired following rupture or incision of infected thyroglossal cyst

6. Usually found in subhyoid portion of tract 75% present as midline swellings Remainder can be found as far lateral as lateral tip of hyoid bone The cyst elevates on protrusion of the tongue Can present as an infected cyst due lymphoid tissue in the cyst wall If infected, aspirate cyst rather than incise prevents formation of thyroglossal fistula Treatment Sistrunk Operation Transverse skin crease incision Platysma flaps raised. Cyst dissected Middle 1/3 of hyoid and any suprahyoid tract extending into the tongue dissected Clinical features of Thyroglossal cysts INDEX

7. Fistulography: “note the position of the fistula anterior to the trachea (black air)” The classical site for a thyroglossal fistula Thyroglossal fistula INDEX

15. Anatomy : Site In front of lower Part of neck Shape butterfly

16. Structure Each lobe Pear shaped 2 *1*1 inches Its apex lies at Level of oblique line Of thyroid cartilage & base reach 5 th . Or 6 th . Tracheal ring Isthmus lies on 2 nd . ,3 rd . ,4 th , Tracheal rings Pyramidal lobe It is connected to hyoid bone By fibrous band ( levator glandulae ) thyroid 2 capsules : *true C.T. capsule around gland *false outer capsule from pretracheal fascia Pretracheal fascia

17. *Skin , superficial fascia (containing platysma) , deep fascia. * sternomastoid * sternothyroid & sternohyoid * superior belly of omohyoid Relations Antero lateral

18. Upper part lower part medial pharynx larynx R.L.N. trachea esophagus

19. posterior Carotid sheath C.C.A I.J.V. Sympathetic chain Vagus nerve Anasa cervicalis Inferior thyroid artery

20. 1- arterial : Blood supply superior thyroid artery Branch from E.C.A. Related to E.L.N. Inferior thyroid artery Branch from thyrocervical trunk Which is branch of 1 st . Part of subclavian Related to R.L.N. Others Thyroid ima artery from aorta ( may be abscent ) Accessory tracheal & esophageal braches

21. 2- venous : Superior thyroid vein drain to I.J.V. middle thyroid vein drain to I.J.V. inferior thyroid veins drain to left innominate vein The middle thyroid vein Is the shortest soit is the 1 st . To be ligated

24. 3- lymphatic : Medial part Peripheral part Prelaryngeal L.N. ( Poirier ) Pretracheal L.N. ( Delphie ) Mediastinal L.N. Upper deep cervical L.N. Lower deep cervical L.N.

25. Superior laryngeal nerve internal laryngeal nerve Sensory to m.m of Larynx above vocal cords external laryngeal nerve Motor to cricotyroid Muscle It is closely related To Superior thyroid artery Right R.L.N. Turns around 1 st . Part Of subclavian artery Left R.L.N. Turns around arch of aorta Both supply all Intrinsic muscles Of larynx except (cricothyroid ) & m.m below vocal cords

33. Nodular goitre

34. Thyrotoxicosis

35. Def.: It is an increase in the thyroxin production by the thyroid gland & this is either due to the whole gland enlargement or a thyroid nodule thyroxin

36. What happens? An increase in thyroxin secretion. Increase of response of the body cells to adrenaline. So signs & symptoms of the disease occur.

37. Symptoms 1-Neurological manifestations: Which usually occur in the young age. These manifestations are : *Inosomnia.

38. *Nightmares. *Tremors in hand and feet.

39. *Nervousness

40. 2-Cardiologic manifestations: It occurs to the elder patients. It is represented by: Tachycardia & arrythmia. It may reach heart faliure.

41. 3- thyroid paradox: Decrease in weight although increase in appetite. 4- increase sweating & sense of hotness in weather

42. 5-Polyurea & diahrea 6-Fatigability

43. 7-oesteoporosis. 8- Thyrotoxic goiter

45. Signs : (a) General examination : Body mass index ( BMI ) is usually less than 20 Kg/m2 (I) Underweight :

46. (II) Cutaneous changes : * Moist warm extremities. * Profuse sweating & flushed face * Falling of hairs * Clubbing of fingers & toes * Soft and brittle nails . * Pretibial myxoedema : Usually bilateral. Non pitting. Self limiting.

47. (III) Nervous signs : Irritability and anxiety. Fine tremors in the tongue & in the fingers hands • Reflexes are exaggerated. Myopathy weakness of the proximal limb muscles. (IV) cardiovascular signs : 1-PULSE Rate : Tachycardia with sleeping pulse up to 100 – 120 / min. Character : Big pulse volume (water - hummer character).

48. Rhythm : All types of arrhythmia except heart block & V.F. 2- B.P. : Systolic B.P. is high but diastolic is usually low or normal (due to peripheral V.D) that Increase pulse pressure. 3. HEART : Accentuation of heart sounds. Functional soft systolic murmur maximum over pulmonary & aortic area.

49. (V) Eye manifestations : A. Exophthatmos ( > 50 % of cases ) : TYPES : a)Apparent ( mild = false) exophthalmos : widening of the palpebral fissure due to spasm of Muller's muscle.

50. b)True exophthalmos : actual protrusion of the eyeballs. It is an autoimmune disease Infiltration of retro bulbar tissue with inflammatory cells & accumulation of inflammatory fluids. Probably due to cross- reaction of thyroid antigen & eye (Schwartz ) C.T showing infiltration of Retro bulbar spaces True exophthalmos

51. 1. Rosenbach's sign: Tremors on closing eye lids. B. Certain eye signs : 2. Stellwag's sign : Staring look with infrequent blinking. 3. Dalrymple's sign : rim of sclera is seen between cornea and the upper lid. 4. Von Graef's sign : Lagging of the upper eye lid 5. Joffroy's sign : loss of forehead corrugation when looking up 6. Moebius' sign : Lack of convergence (due to ocular myopathy )

52. (b) Local examination : Site : Swelling in the lower part of the front of the neck. Size : slight to moderate enlargement. Shape : symmetrical. Surface: smooth. Skin overlying: is warm. Special character : moves up & down with deglutition. Consistency : soft. Edge: well defined. Pulsations & thrills : are detected usually at the upper poles (V) Reticulo - endothelial signs: Just palpable spleen and may be generalized lymphadenopathy

54. Lid retraction

55. What are investigations? *Free T3 , T4 & TSH. . *Neck ultrasound. *Thyroid scan using radioactive iodine or Tc99

57. Increased uptake scan

58. Treatment There are 3 lines of treatment: 1-Medical treatment: A-Thiourea group. B-Indral.

59. 2- Surgical intervention: We make subtotal thyroidectomy after preparation. 3-Treatment using radioactive iodine

66. © Thyroid Isotope scan Cold nodule Index Thyroid imaging

67. © Index Thyroid imaging NORMAL Iodine uptake is represented here in a colour scale Hot nodule – Rt. lobe Cold nodule – Rt. lobe Thyroid Isotope scan

68. © Thyroid US Index Normal Thyroid nodule

69. © Fine needle aspiration cytology of thyroid swelling Index

70. © Physiological goiter in a 14 year old female Simple diffuse hyperplastic (euthyroid) goiter Results from stimulation of the gland by TSH in response to chronically low level of circulating thyroid hormone . Persistent growth stimulation causes diffuse hyperplasia; all lobules are composed of active follicles. Iodine uptake is uniform. Diffuse hyperplasia is reversible if TSH stimulation ceases With pregnancy (High metabolic demands) Index Endemic iodine deficiency goiter –starts as diffuse hyperplasia but nodules appear early

71. © Simple (euthroid) multinodular goiter Pathology: As a result of flutuating stimulation, a mixed pattern develops in the gland with arias of active lobules & areas of inactive lobules Active lobules are initialy more active and vascular. Hemorrhage will cause central necrosis Necrotic lobules coalesce to form nodules Nodules are either filled with colloid ( which is iodine free), or new but inactive follicles Repetition of this process results in a NODULAR GOITER Most nodules are inactive. Active follicles are present only in the internodular tissue. Index

72. © Nodular goiter – (cut section) This is a cut section of a nodular goiter showing nodules of various sizes with secondary hemorrhage, necrosis and cystic change

73. © Simple (euthroid) multinodular goiter One macroscopic nodule may predominate giving the impression of a solitary thyroid nodule. US is useful to detect other small nodules that are not palpable clinically Nodules may be colloid or cellular Common complications in thyroid nodules Cystic degeneration Hemorrhage (nodule becomes painful and increases in size acutely) (D.D. carcinoma, autoimmune throiditis) Calcification ( if extensive may give a hard sensation confusing with malignancy) Complications of SNG : Tracheal obstruction (by gross latera displacement or compression in retrosternal extension) 2ry thyrotoxicasis Carcinoma (uncommon but more found in endemic areas – usually follicular) Index

74. © Toxic (hyperthyroid) goiter 1ry (Graves disease) 2ry nodular goiter Hot nodule in 2ry nodular toxic goiter Diffuse and intense uptake of radioctive iodine Different appearance in thyroid scan Index

75. © EXOPHTHALMUS in GRAVS Ds. Index

76. © Large multinodular toxic goiter: Clinically, one large nodule predominates Thyroid scan shows: Hot nodules on the apex of the left lobe and on the middle of the right lobe and cold nodules on the right lobe and on the isthmus. The treatment is surgical Toxic multinodular goiter Index

77. © Index Nodular Goiter

78. © Simple nodular goiter What is the D.D. of a cold nodule in a thyroid scan Index larger colloid cyst at the left lower pole and a smaller colloid cyst at the right lower pole Such cysts could appear as "cold" nodules on a thyroid scan. Index

79. © Solitary thyroid nodules Index Malignant 15% Benign 85% Papillary (most common) Hyperplastic or colloid nodules (common) Follicular (less common) Follicular adenoma (less common) Medullary & anaplastic (rare) Cysts

80. © A 16-year-old patient with an asymptomatic palpable thyroid nodule noticed on routine physical examination Surgical specimen of a thyroid lobe of the same patient with papillary carcinoma Index

81. © Gross specimen of thyroid gland containing partially cystic mass lesions with papillary projections What is the significance and differential diagnosis of a cold nodule in the thyroid gland? Papillary carcinomas of the thyroid Thyroid Index

82. © Solitary nodule in the base of the left lobe of the thyroid The nodule exceeds the anterior margin of the capsule The nodule proved to be malignant U.S. showing a solitary thyroid nodule. The nodule is very hypoechoic, inhomogeneous; irregular and vague borders, Anterior margin of the capsule looks broken by the nodule Large cold nodule on the base of the left lobe Solitary thyroid nodule Index

83. © Retrosternal Goiter Index

84. © Retrosternal goiter displacing trachea in plain X-ray chest & CT upper chest Index

85. © Large nodular goiter, with retrosternal extension causing mediastinumcompression of the veins Enlargement of the upper mediastinum and right deviation of the trachea owing to large nodular goiter Large retrosternal nodular goiter with Rt. Deviation of the trachea ( T ) . Note calcifications (white spots) in the gland T

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