Download THE THYROID GLAND

THYROID GLAND
Begashaw M (MD)
Anatomy
Goiter
 Generalized
enlargement of the thyroid
gland which is normally impalpable
Classification
1. Simple-Euthyroid
_Diffuse hyper plastic
_(Multinodular)
2. Toxic
_Diffuse - Grave’s
disease
_Nodular
_Toxic adenoma
3. Neoplastic
_ Benign
_Malignant
4. Inflammatory
_Autoimmune
_Infectious
_Acute –bacterial/viral
_Chronic -tuberculous
Thyroid lesions
Simple Goiter

Patho - physiology
 enlargement of the thyroid gland
 stimulation of the thyroid gland by high
levels of circulating TSH
 common in Females
Etiology
_Iodine deficiency
_Goitrogenscabagge
_Drugs iodine,lithium
_Defective hormone synthesis
_peripheral resistance to thyroid hormone
Diffuse hyper-plastic goiter

Persistent stimulation by TSH causes
diffuse hyperplasia of the thyroid gland
 Soft, diffuse & large
 Usually occurs at puberty , pregnancy
 Areas of active lobule & inactive lobules
Goiter –simple
Nodular goiter

Nodular goiter
-solitary
-multinodular
 Nodule
-colloid when filled with colloid
-cellular
 Secondary changes
-cystic degeneration
-hemorrhage
-calcification
Diagnosis

Clinical presentation
_Discrete swelling in one lobe
-Solitaryisolated
-Dominant noduleabnormality Elsewhere
_smooth, firm
_painless
_moves with swallowing
_ euthyroid
Investigation
TFT  T3, T4, TSH
 CXR/Thoracic inlet x-rayscalcification,
tracheal deviation & compression
 Thyroid antibody titers
 FNACytology

Complications
Compression stridor, dysphagia, pain, &
hoarseness
 Secondary thyrotoxicosis
 Carcinoma malignant changes of the
follicular type

Retrosternal goiter
Prevention

Introduction of iodized salt
 Thyroxin of 0.1mg daily
 Nodular stage is irreversible
Indication of surgery

Cosmetic
 Tracheal compression
 When malignancy cannot be excluded
 Options of surgery
_Near total thyroidectomy
_Subtotal thyroidectomy
Toxic goiters

Thyrotoxicosis - increased metabolic rate
due to high level of circulating thyroid
hormone
 8X more commonly seen in females than
males
Clinical features

symptoms
_Loss of weight in spite
of good appetite
_preference of cold
_Palpitation
_Tiredness
_Emotional liability

signs
_excitability
_presence of goiter
_hot & moist palms
_exophthalmus in
primary type
_tachycardia with
cardiac arrhythmia
Diffuse Toxic GoiterGraves
Disease

Is a diffuse vascular goiter appearing at the
same time as symptoms of hyperthyroidism
 Occurs in younger women
 Frequently associated with eye signs
 Hypertrophy & hyperplasia are due to
abnormal TS antibodies
 F > M = 7:1
Graves disease
Toxic nodular goiter

A simple nodular goiter is present for a long
time before hyperthyroidismsecondary
thyrotoxicosis
 Seen in middle aged/elderly people
 Less frequently associated with eye signs
 Nodules are inactive
 Intermediate thyroid tissue is involved in
hyper secretion
Toxic nodule

Solitary hyperactive nodule which may be
part of a generalized nodularity or a true
toxic adenoma
 is autonomous
 not due to TS antibodies
 normal thyroid tissue surrounding the
nodule is suppressed & inactive
Diagnosis

Clinical picture
 T3,T4,TSH
 Isotope scanning
Treatment
Antithyroid drugs
 Surgery
 Radioiodine

Anti thyroid Drugs

used to resume the patient to a euthyroid
state maintain this for a prolonged period
 cannot cure a toxic nodule
Surgery

Preoperatively, the patient must be prepared
with antithyroid drugs so that the patient
becomes euthyroid
 Subtotal thyroidectomy
Post-operative complications

Hemorrhage
 Respiratory obstruction
 Recurrent laryngeal nerve paralysis
 Thyroid insufficiency
 Parathyroid insufficiency
 Thyrotoxic crisis (storm)
 Wound infection
Thyroid Tumour



BenignFollicular adenoma
Malignant
Primary
- EpithelialFollicular,Papillary,Anaplastic
- Para follicularMedullary
- Lymphoid cellslymphoma
 Secondary
- Metastatic
- Local infiltrations
Benign Tumours

Follicular adenomas
-solitary nodules
-distinction between a follicular carcinoma &
adenoma can only be made by histological
examination
-Treatment Lobectomy
Malignant Tumors

Clinical feature
-Thyroid swelling
-Enlarged cervical lymph node -papillary
carcinoma
-Recurrent laryngeal nerve paralysis –locally
advanced disease
-Anaplastic-hard, irregular, infiltrating
Thyroid Cancer
Investigations

TFTT3,T4,TSH
 FNA
 Antibody assay
 Radio isotope scanning
Treatment/Prognosis
_Surgerytotal thyroidectomy
_Prognosis Histological type, age, extra
thyroid spread, & size of tumor
_ Males > 40 yrs of age & Females >50 yrs
have worse prognosis
_Distant metastatic diseaseworse prognosis
Anaplastic Carcinoma

Mainly in elderly woman
 Local infiltration
 Epread by lymphatics & blood stream
 Extremely lethal tumors with death
occurring in most cases within month
 Present in advanced stages with tracheal
obstruction
 Radiotherapy