thyroid gland. - the first endocrine gland to develop. - endodermal origin. - originates from the...

Thyroid GlandThyroid Gland


- The first endocrine gland to develop.- The first endocrine gland to develop.- Endodermal origin.Endodermal origin.- Originates from the ventral embryologic digestive tract.Originates from the ventral embryologic digestive tract.- midline diverticulum (foramen cecum of tongue) – 4midline diverticulum (foramen cecum of tongue) – 4thth

week → descends as median thyroid component →week → descends as median thyroid component →

ISTHMUSISTHMUS- True histological differentiation 8 -11 week.True histological differentiation 8 -11 week.

Thyroid GlandThyroid Gland- The lateral Thyroid component develops on each side from the The lateral Thyroid component develops on each side from the

caudal pharyngeal endoderm.caudal pharyngeal endoderm.- Arises latter than the Medial.Arises latter than the Medial.- Fuse with the posterior portion of the median component on each Fuse with the posterior portion of the median component on each

side → C Cell migration from the neural crest. side → C Cell migration from the neural crest. - Basic Glandular Function begins at the 3 month of Gestation. Basic Glandular Function begins at the 3 month of Gestation.

Thyroid GlandThyroid Gland- Functional Disorders:Functional Disorders:

Hyper Thyroidism: Hyper Thyroidism: - Grave’s dibease- Grave’s dibease - Toxic Multinodular Goiter- Toxic Multinodular Goiter

- Solitary Toxic Adenoma- Solitary Toxic AdenomaHypothyroidismHypothyroidism

Thyroiditis: - Hashimoto ThyroiditisThyroiditis: - Hashimoto Thyroiditis - Painelss or Postpartum Thyroiditis- Painelss or Postpartum Thyroiditis - Subactue Thyroiditis- Subactue Thyroiditis

- Amiodarone Induced Thyroiditis or- Amiodarone Induced Thyroiditis or Thyrotoxicosis.Thyrotoxicosis.

- Acute Thyroiditis- Acute Thyroiditis - Riedel’s Thyroiditis- Riedel’s Thyroiditis


Nodular Thyroid diseaseNodular Thyroid disease

- Nontoxic Multinodular GoiterNontoxic Multinodular Goiter

- Solitary or Dominant Thyroid Nodule.Solitary or Dominant Thyroid Nodule.


MalignancyMalignancy

- Incidence 4/100.000 population / year.Incidence 4/100.000 population / year.- Wide spectrum of behavior.Wide spectrum of behavior.- 98% of Thyroid cancer are well differentiated.98% of Thyroid cancer are well differentiated.- More or less same surgical approach.More or less same surgical approach.


MalignancyMalignancy

II Papillary Carcinoma – 80%Papillary Carcinoma – 80%

- Follicular variant- Follicular variant

- Microcarcinoma- Microcarcinoma

IIII Follicular Carcinoma – 10-20%Follicular Carcinoma – 10-20%

- Minimally Invasive- Minimally Invasive

IIIIII Hurtel Cell Carcinoma – 5%Hurtel Cell Carcinoma – 5%

IVIV Medullary Carcinoma – 7%Medullary Carcinoma – 7%

Parafollicular C CellsParafollicular C Cells

VV Anaplastic Carcinoma – 1-2%Anaplastic Carcinoma – 1-2%

VIVI Thyroid Lymphoma - < 5%Thyroid Lymphoma - < 5%

- non Hodgkin (B cell origin)- non Hodgkin (B cell origin)

- usually arise from Hashimoto Thyroiditis- usually arise from Hashimoto Thyroiditis


Treatment of MalignancyTreatment of Malignancy- SurgerySurgery- Radioiodine TherapyRadioiodine Therapy- External Beam RadiotherapyExternal Beam Radiotherapy- TSH SuppressionTSH Suppression


Complication of SurgeryComplication of Surgery1.1. BleedingBleeding

2.2. Airway ObstructionAirway Obstruction

3.3. RLN InjuryRLN Injury

4.4. HypoparathyroidismHypoparathyroidism

5.5. Injury EBSLNInjury EBSLN

Parathyroid GlandParathyroid Gland

4 glands: 2 superior (LT+RT)4 glands: 2 superior (LT+RT)

2 inferior LT + RT2 inferior LT + RT- 5-7mm x 0.5-2mm5-7mm x 0.5-2mm- 30-50mg30-50mg- Superior glands: - post surface of thyroid glandSuperior glands: - post surface of thyroid gland

were RLN pierces the larynxwere RLN pierces the larynx

- No variation- No variation

Inferior glands: - VariableInferior glands: - Variable

The surgeon must have a thorough The surgeon must have a thorough

understanding of the anatomic variations.understanding of the anatomic variations.


AnatomyAnatomy4-54-5thth week -> 4 pharyngeal pouches week -> 4 pharyngeal pouches

44thth → Sup parathyroid + Lat thyroid → Sup parathyroid + Lat thyroid

Remain in close association with the upper pole of theRemain in close association with the upper pole of the

Thyroid.Thyroid.

33rdrd → Inf parathyroid – Descends with the Thymus → Inf parathyroid – Descends with the Thymus

Extremely variable migrationExtremely variable migration- Supernumerary: 6 -15%Supernumerary: 6 -15%- Intrathyroid parathyroid – rareIntrathyroid parathyroid – rare


PhysiologyPhysiology

- CalciumCalcium- PhosphatePhosphate- Regulation:Regulation: - GI tract - GI tract

- Skeleton- Skeleton

- Kidneys- Kidneys

- PTH- PTH

- Vit D- Vit D

- Calcitonin- Calcitonin


HyperparathyroidismHyperparathyroidism

- Primary Hyperparathyroidism:Primary Hyperparathyroidism: Adenoma – 80%Adenoma – 80%

Double Adenoma – Double Adenoma – 6%6%

Hyperplasia – 12-Hyperplasia – 12-14%14%

- Secondary Hyperparathyroidism Secondary Hyperparathyroidism - Tertiary HyperparathyroidismTertiary Hyperparathyroidism- Parathyroid CarcinomaParathyroid Carcinoma

Primary HyperparathyroidismPrimary Hyperparathyroidism

Laboratory FindingsLaboratory FindingsSerumSerum UrineUrine

-- Ca Ca - - Ca / 24h Ca / 24h

-- P P - - P / 24h P / 24h

-- PTH PTH - Tubular - Tubular

reabsorption of P < 30%reabsorption of P < 30%

-- Mg (5-10%) Mg (5-10%)

-- Bicarbonate Bicarbonate

Hyperchloremic Metabolic AcidosisHyperchloremic Metabolic Acidosis

A ratio > 30 cl/p = Hyperparathyroidism.A ratio > 30 cl/p = Hyperparathyroidism.

Primary Primary HyperparathyroidismHyperparathyroidism

LocalizationLocalization

- U.SU.S- 99m technetium sestamibi scintigraphy 99m technetium sestamibi scintigraphy - CTCT- MRIMRI- Versus Sampling Versus Sampling


Indication for Surgery*Indication for Surgery*- Elevated serum calcium (>1mg/dL above normal)Elevated serum calcium (>1mg/dL above normal)- History of an episode of life – threatening HypercalcemiaHistory of an episode of life – threatening Hypercalcemia Createnin clearanceCreatenin clearance- Kidney stonesKidney stones- Markedly Markedly 24h calcium excretion 24h calcium excretion- Substantially Substantially bone mass (Tscore < - 2.5) bone mass (Tscore < - 2.5)

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* NIH Consensus* NIH Consensus


SurgerySurgery

- Bilateral Neck Exploration.Bilateral Neck Exploration.- Unilateral Neck Exploration.Unilateral Neck Exploration.- Minimally Invasive Parathyroidectomy.Minimally Invasive Parathyroidectomy.- Total Parathyroidectomy Total Parathyroidectomy Auto transplantation. Auto transplantation.

thyroid gland. - the first endocrine gland to develop. - endodermal origin. - originates from the...

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