Thyroid Gland

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Thyroid Gland
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Thyroid Gland

• - The first endocrine gland to develop.
• Endodermal origin.
• Originates from the ventral embryologic
  digestive tract.
• midline diverticulum (foramen cecum of tongue)
  4th
• week ? descends as median thyroid component
  ?
• ISTHMUS
• True histological differentiation 8 -11 week.

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Thyroid Gland

• The lateral Thyroid component develops on each
  side from the caudal pharyngeal endoderm.
• Arises latter than the Medial.
• Fuse with the posterior portion of the median
  component on each side ? C Cell migration from
  the neural crest.
• Basic Glandular Function begins at the 3 month
  of Gestation.

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Thyroid Gland

• Functional Disorders
• Hyper Thyroidism
• - Graves
  dibease
• - Toxic
  Multinodular Goiter
• - Solitary Toxic Adenoma
• Hypothyroidism
• Thyroiditis - Hashimoto Thyroiditis
• - Painelss or Postpartum
  Thyroiditis
• - Subactue Thyroiditis
• - Amiodarone Induced Thyroiditis or
• 
  Thyrotoxicosis.
• - Acute Thyroiditis
• - Riedels
  Thyroiditis

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Thyroid Gland

• Nodular Thyroid disease
• Nontoxic Multinodular Goiter
• Solitary or Dominant Thyroid Nodule.

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Thyroid Gland

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

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Thyroid Gland

• Malignancy
• I Papillary Carcinoma 80
• - Follicular variant
• - Microcarcinoma
• II Follicular Carcinoma 10-20
• - Minimally Invasive
• III Hurtel Cell Carcinoma 5
• IV Medullary Carcinoma 7
• Parafollicular C Cells
• V Anaplastic Carcinoma 1-2
• VI Thyroid Lymphoma - lt 5
• - non Hodgkin (B cell origin)
• - usually arise from Hashimoto Thyroiditis

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Thyroid Gland

• Treatment of Malignancy
• Surgery
• Radioiodine Therapy
• External Beam Radiotherapy
• TSH Suppression

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Thyroid Gland

• Complication of Surgery
• Bleeding
• Airway Obstruction
• RLN Injury
• Hypoparathyroidism
• Injury EBSLN

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Parathyroid Gland

• 4 glands 2 superior (LTRT)
• 2 inferior LT RT
• 5-7mm x 0.5-2mm
• 30-50mg
• Superior glands - post surface of thyroid gland
• were RLN pierces the larynx
• - No variation
• Inferior glands - Variable
• ?
• The surgeon must have a thorough
• understanding of the anatomic
  variations.

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Parathyroid Gland

• Anatomy
• 4-5th week -gt 4 pharyngeal pouches
• 4th ? Sup parathyroid Lat thyroid
• Remain in close association with the upper pole
  of the
• Thyroid.
• 3rd ? Inf parathyroid Descends with the
  Thymus
• 
  Extremely variable migration
• Supernumerary 6 -15
• Intrathyroid parathyroid rare

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Parathyroid Gland

• Physiology
• Calcium
• Phosphate
• Regulation - GI tract
• - Skeleton
• - Kidneys
• - PTH
• - Vit D
• - Calcitonin

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Parathyroid Gland

• Hyperparathyroidism
• Primary Hyperparathyroidism Adenoma 80
• Double Adenoma 6
• Hyperplasia 12-14
• Secondary Hyperparathyroidism
• Tertiary Hyperparathyroidism
• Parathyroid Carcinoma

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Primary Hyperparathyroidism

• Laboratory Findings
• Serum
  Urine
• -? Ca - ? Ca / 24h
• -? P - ? P / 24h
• -? PTH - Tubular
• 
  reabsorption of P lt 30
• -? Mg (5-10)
• -? Bicarbonate
• ?
• Hyperchloremic Metabolic Acidosis
• A ratio gt 30 cl/p Hyperparathyroidism.

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Primary Hyperparathyroidism

• Localization
• U.S
• 99m technetium sestamibi scintigraphy
• CT
• MRI
• Versus Sampling

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Parathyroid Gland

• Indication for Surgery
• Elevated serum calcium (gt1mg/dL above normal)
• History of an episode of life threatening
  Hypercalcemia
• ? Createnin clearance
• Kidney stones
• Markedly ? 24h calcium excretion
• Substantially ? bone mass (Tscore lt - 2.5)
• --------------------------------------------------
  ---------------------------
• NIH Consensus

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Parathyroid Gland

• Surgery
• Bilateral Neck Exploration.
• Unilateral Neck Exploration.
• Minimally Invasive Parathyroidectomy.
• Total Parathyroidectomy ? Auto transplantation.