GOITREPRESENTERS: HAMISI MKINDI,MD5 SHIJA CHARLES,MD5 THERESIA LUFYO,MD5

MODERATORS Dr.FASSIL G. Dr.MAYOKA R. Dr.Fr.GINGO

Learning objectives

Definition Surgical anatomy

and embryology of thyroid gland

Etiology Classification Pathophysiology Clinical

presentation

Workup Treatment Complications Prevention

DEFINITION

Goiter can be defined as enlargement of the thyroid gland irrespective of its pathology

THYROID

Derives its name from thyroid cartilage Anterior part of neck 20-25gm Functional unit=lobule Each lobule =24-40 follicles

SURGICAL ANATOMY

BLOOD SUPPLY

NERVE SUPPLY

ARTERIES AND NERVES

EMBRYOLOGYDv from TGD(median bud of pharynx)which

passes from foramen caecum at base of the tongue to thyroid isthmus

First of the body's endocrine glands to develop, on approximately the 24th day of gestation.

2 main structures: the primitive pharynx and the neural crest.

EMBRYOLOGY

The inferior parathyroid glands arise from the dorsal wing of the third pharyngeal pouch.

The initial descent of the thyroid gland follows the primitive heart and occurs anterior to the pharyngeal gut. At this point, the thyroid is still connected to the tongue via the thyroglossal duct.

PHYSIOLOGY

THYROID HORMONES

Mental growth and developmentPhysical growthBMRSensitivity to catecholamines

ETIOLOGY OF GOITRE

Factors associated with goiter formation can be classified as follows:-Hereditary factorsHormonal factorsDietary factorsPharmacological factorsPhysiological factorsEnvironmental factorsPathological factors

Hereditary factorsInherited defect of thyroid hormone

synthesis Enzymatic defect deficiencyDyshormonogenesis

Familial goitre

Hormonal factorsThyroid hormone dysfunction

Hyperthyroidism (overproduction of thyroid hormones)

Hypothyroidism (underproduction of thyroid hormones)

Dietary factors

Dietary iodine deficiencyGoitrogens:-

Cabbage endemic goitre

Pharmacological factorsUse of goitrogen drugs like para-

aminosalicylic acid (PAS), thiocyanate and antithyroid drugs [e.g. thiouracil, carbimazole] hypothyroidism

Physiological factorsIncreased metabolic demand of

thyroid hormones e.g. during pregnancy or puberty physiological goitre

Environmental factors

Exposure to radiations Thyroid cancer

Hypothyroidism

Pathological factorsIntrinsic thyroid gland diseases

Inflammatory goitresNeoplastic goitres-Benign adenoma(follicular adenoma)-MalignantA.Primary

Well differentiated, Poorly differentiated, Arising from parafollicular cells

B.Secondary

CLASSIFICATION

Etiological classificationEpidemiological classificationAnatomical classificationPathological classificationFunctional classificationMorphological classification

Etiological classificationPhysiological goitre

Goitres resulting from increased metabolic demand of thyroid hormones e.g. during pregnancy or puberty

Pathological goitreGoitres resulting from diseases

affecting the thyroid gland e.g. Neoplastic or inflammatory conditions

Epidemiological classificationFamilial goitres

goitres that run in families as a result of Inherited defect of thyroid hormone synthesis

Endemic goitresdefined as thyroid enlargement affecting

a significant number of inhabitants of a particular locality

Sporadic goitresgoitres that run sporadically

Anatomical classification

Cervical goitreGoitre situated on the anterior aspect of

the neckRetrosternal goitre

Goitre extends downward and get situated behind the sternum

Intrathoracic goitreThe type of goitre which extends into

thoracic cavity

Pathological classificationSimple goitresToxic goitres Neoplastic goitresInflammatory goitresMiscellaneous (Other rare types)

Functional classificationToxic goitre

Type of goitre associated with thyroid hyperfunction (hyperthyroidism)

Non-toxic Type of goitre associated with thyroid

hypofunction (hypothyroidism) or normal thyroid function (Euthyroid)

Morphological classificationAccording to the texture of the

glandDiffuse goitreNodular goitre

Solitary nodular goitreMultinodular goitre

PATHOPHYSIOLOGY

The pathophysiological consequences of goitres results from one of the following:-The effect of thyroid hormone

dysfunctionThe effect of enlarged thyroid glandThe effect of primary disease causing

goitre

Effect of thyroid hormone dysfunction

Thyroid hyperfunction (hyperthyroidism)

Features of hyperthyroidism

Thyroid hypofunction (hypothyroidism)

Features of hypothyroidism

Effect of enlarged thyroid gland

Effect on the trachea dyspneaEffect on the esophagus

dysphagiaEffect on the superior venacava

distended neck veinsEffect on the recurrent laryngeal

nerve horsiness of voice

Effect of primary disease causing goitre

The effect depends on the underlying disease

CLINICAL PRESENTATION

History (Symptoms)Physical examination (Signs)

History (Symptoms)Age SexMain complaints

Anterior neck swellingDurationMode of onsetRate of growthAssociated pain

History (Symptoms)… Pressure-related symptoms

Dysphagia, dyspnoea, hoarseness of voice, neck vein engorgement etc

Review of systems to assess toxicityCNS- tremors, irritability, mental

disturbance CVS- palpitation, dyspnoea, orthopnoeaGI- change of appetite, constipation,

diarrhoeaMSS- bone pain, weight change, heat or

cold preference, excessive sweating

History (Symptoms)…….. Past medical history

Previous medication, previous h/o irradiation

Family and social historyH/o goitre in the family or in the

community

Physical examination General examinationLocal examinationSystemic examination

General examinationLook for four cardinal features of

toxicity namely:-ExophthalmosisTachycardiaTremorMoist skin

Local examinationInspectionPalpationPercussionAuscultation

Systemic examinationCentro nervous system Cardiovascular SystemRespiratory system

WORK UP

Laboratory studiesImaging studies Endoscopic studiesHistopathology

Laboratory studiesSerum TSH(0.3-5IU/ml)Serum T3(1.5-3.5nmol/l)Serum T4(55 – 150nmol/l)Disease T3 T4 TSH

Thyrotoxicosis Increased Increased Supressed

T3 toxicosis 2X Normal Suppressed

Hypothyroidism Low/normal Low Increased

Labs cont…

Serum thyroglobulinSerum cholesterolThyroid autoantibody levelsThyroid scintigraphy

Imaging studiesPlain x-ray of the neckThyroid ultrasoundThyroid radioisotope scanCT scan/MRIBarium swallow

Plain x-ray of the neckPlain radiography of the neck may

reveal the following:-Tracheal deviation or

compressionCalcification within the goitre

Thyroid ultrasound Help to determine the

physical characteristics of the goitre and used to:- distinguish solid from

cystic nodules assess whether more

than one nodule exists to assess the exact size

and shape of the thyroid gland

Aid in ultrasound guided FNAC

Thyroid radioisotope scan Used to determine the functional activiity by

distinguishing a nodule as hot, warm, or cold, based on the relative amount of uptake of radioactive isotope Hot nodules take up excessive amounts of

isotope and indicate autonomously functioning nodules

Cold nodules does not radioactive isotope and therefore indicate hypofunctional or nonfunctional thyroid tissue

Warm nodules appear gray and suggest normal thyroid function

The radioactive isotopes that are most commonly include 123-Iodine, 99m-Technetium and 131-Iodine

CT scan/MRIGive excellent anatomical detail of

thyroid swelling but have no role in the first line of investigation

Help to assess recurrence and intrathoracic or retrosternal goitres

Barium swallowTo assess compression of the

esophagus

Endoscopic studiesIndirect laryngoscopy

To assess the mobility of the vocal cord

HistopathologyFine needle aspiration cytology (FNAC)Open biopsy

TREATMENT

Medical treatmentRadioiodine Surgery

Medical treatmentLugol’s iodine

thyroid hormone synthesis vascularity

Antithyroid drugs eg CarbimazoleUsed to restore the patient to a euthyroid

state -adrenergic blockers E.g. propranolol

tachycardia & palpitation Used to restore the patient to a euthyroid It also vascularity

RadioiodineThyroiodine destroys thyroid cells

and as in thyroidectomy reduces the mass of functioning

SurgeryIndicationsPreoperative careIntraoperative care Postoperative care

IndicationsCosmetic purposeSuspected malignancyToxic goitrePressure symptoms

Preoperative careCorrect anemia, mobilize blood donor Treatment of intercurent disease or

infectionsThe thyroid functional status should be

determinedThe patient should be made euthyroid

Preoperative care……Admit the patient a day before

operationAnesthetic visitAn informed written consent for

operation and anaesthesia

Intraoperative careTypes of surgery (Thyroidectomy)

Subtotal thyroidectomyNear-total thyroidectomyTotal thyroidectomyThyroid nodulectomy

Postoperative careIv fluidAnalgesicsAntibiotics Monitor vital signs

COMPLICATIONS

Complications related to enlarged glandComplications related to thyroidectomy

Complications related to enlarged gland

Tracheal obstruction airway obstruction

Secondary thyrotoxicosisMalignant transformation

Complications related to thyroidectomy

Haemorrhage Respiratory obstruction Recurrent laryngeal nerve palsy Thyroid storm Thyroid insufficiency Parathyroid insufficiency Wound infection Hypertrophic scar Keloids

PREVENTION

PrimarySecondaryTertiary