goitre
TRANSCRIPT
GOITRE
Dr Echebiri, PromiseState House Medical Centre, Aso Rock, Abuja.
5th December,2011.
CONTENTS• Definition• Overview• Background• Pathophysiology• Classification• Presentation• Investigations• Differential Diagnoses• Treatment• Prognosis
DEFINITION
An enlarged thyroid gland.
-Clinically palpable gland.-Gland enlargement more than twice of the
normal size.
OVERVIEW
• Geography: Worldwide, the most common cause of goiter is iodine deficiency.
Approximately 800million people subsist on iodine-deficient diet.
In industrialized countries,goiter is more often due to Hashimoto’s thyroiditis.
OVERVIEW
• Sex: The female-to-male ratio is 4:1. Thyroid nodules are more likely to be
malignant in menThe frequency of goiters decreases with
advancing age. although the incidence of thyroid nodules increases with advancing age.
• Race: No racial predilection exists.
BACKGROUNDThyroid gland surface marking
BACKGROUNDHypothalamo-Pituitary-Thyroid Axis
BACKGROUNDThyroid anatomy
BACKGROUNDThyroid physiology
BACKGROUND
• TRH:Produced by Hypothalamus. Release is pulsatile,circadian. Downregulated only by T3.
Travels through portal venous system to adenohypophysis. Stimulates TSH formation.
• TSH: Produced by Adenohypophysis Thyrotrophs.Up regulated by TRH .Down regulated by T4, T3.
BACKGROUND
Travels through portal venous system to cavernous sinus, then thyroid gland. Stimulates several processesIodine uptakeColloid endocytosisGrowth of thyroid gland.
• Thyroid Hormone: Majority of circulating hormone is T4 98.5% T4 1.5% T3
BACKGROUND
Total Hormone load is influenced by serum binding proteins
Albumin 15% Thyroid Binding Globulin 70% Transthyretin 10%
Regulation is based on the free component of thyroid hormone
BACKGROUNDHormonal interplay
T4,T3
TSH
TRH
PATHOPHYSIOLOGY
CLASSSIFICATIONSBased on growth pattern
Goitre
Nodular
Uninodular:Cysts
Benign thyroid neoplasms
Thyroid cancers
Multinodular:Iodine deficiency
ThyroiditisSarcoidosis
Diffuse
Hypothalamic diseasePituitary disease
Iodine deficiency(endemic, sporadic)Grave’s disease
Thyroid hormone insensitivity
CLASSIFICATIONSBased on size of gland
Grade III
• Invisible
• Palpable
GradeII
• Visible
• Palpable
Grade I
• Visible
• Palpable
• Retrosternal extension
CLASSIFICATIONSBased on activity of gland
Hyperthyroid(toxic)
PRESENTATION
PRESENTATION
• History:Anterior neck swellingPain: Haemorrhage, inflammation, necrosis, or
Malignant transformationCompressive symptoms: Dysphagia, dyspnea,
stridor, plethora or hoarsenessSymptoms of hyperthyroidism or
hypothyroidism
PRESENTATION
• Physical ExaminationCharacterisation of thyroid swellingCheck for signs of
hyperthyroidism/hypothyroidismCheck for signs of compression(Pemberton
manoeuvre).Check for signs of malignancy
PRESENTATIONHyperthyroidism versus Hypothyroidism
INVESTIGATIONS
• Laboratory Studies: TRH TSH Total T3, T4
Free T3, T4
RAIU Thyroglobulin Antibodies: Anti-TPO, Anti-TSHr
INVESTIGATIONS
• Imaging Studies:Ultrasonography:Evaluate goiter size,
consistency, and nodularity. Localize nodules for ultrasonographically guided biopsy.
X Rays:Usually AP and Lateral with thoracic inlet.Retrosternal goitre extension.Presence of calcification.
INVESTIGATIONS
Computed tomography (CT) scanning: Delineate the relationship of the thyroid gland to nearby structures.CT-guided biopsies.
Radionuclide isotope scanning are used to assess thyroid function and anatomy in hyperthyroidism, as shown below.
INVESTIGATIONS
INVESTIGATIONS
Spirometry: The flow-volume loop is useful in determining the functional significance of compressive goiters.
Histology:fine needle aspiration or core biopsy.
DIFFERENTIAL DIAGNOSES
• Pseudogoitre• Thyroglossal cyst• Sublingual dermoid• Lymphadenopathy(bull’s neck).• Thyroid lipomas• Thyroid lymphomas
TREATMENT
• Observation Small goiter Euthyroid Asymptomatic• Medications: Hypothyroidism: Thyroid hormone replacement with
levothyroxine. Hyperthyroidism:May require medications to normalize
hormone levels for example propylthiouacil,Methimazole Inflamed thyroid gland, aspirin or a corticosteroid
TREATMENT
• Surgery: Removing all or part of the thyroid gland-Thyroidectomy.
Large goiters with compressionMalignancyWhen other forms of therapy are not practical
or ineffective• Radioactive iodine: Treatment results in
diminished size of goiter, but eventually may also cause a hypothyroid state.
TREATMENT
• Minimally-invasive modalitiesEndoscopic subtotal thyroidectomyEmbolization of thyroid arteries PlasmaphoresisPercutaneous ethanol injection into toxic
noduleL-Carnitine supplementation may improve
symptoms and may prevent bone loss
PROGNOSIS
• Complications of thyroidectomy:• Thyrotoxic storm• Bleeding• Infection• Hypoparathyroidism• Injury to recurrent laryngeal nerve• Injury to superior laryngeal nerve• Hypothyroidism
PROGNOSIS
• A small percentage of multinodular goiters do lead to hyperthyroidism.
• Benign goiters have a good prognosis,furthermore,the risk of malignant transformation is low.
THANK YOU