goitre

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