Special Surgery 2. Benign Diseases of the Thyroid Gland, and Treatment

I. Goiter and Benign Thyroid Nodules

Definition

Goiter: Enlargement of the thyroid gland
Can be diffuse or nodular
Can be euthyroid, hyperthyroid or hypothyroid
Benign thyroid disease can still need surgery because of compression, hyperfunction or malignancy suspicion

Etiology

Iodine deficiency → Diffuse/simple goiter; still relevant in endemic areas
Autoimmune → Hashimoto thyroiditis, Graves-Basedow disease
Excess iodine or iodine-containing drugs → Thyroid dysfunction by feedback/Wolff-Chaikoff or Jod-Basedow effect
De Quervain/subacute thyroiditis → Painful inflammatory thyroid enlargement
Idiopathic follicular hyperplasia
Benign nodules/cysts/follicular adenoma
Drug-induced → Amiodarone, lithium, interferon and others
Radiation exposure → Nodule/cancer risk
Thyroid malignancy must be excluded in nodular disease

Classification

1. By Morphology

Diffuse goiter → Graves-Basedow disease, Hashimoto thyroiditis, iodine deficiency, thyroiditis
Nodular goiter → Cyst, adenoma, multinodular goiter, cancer

Solitary nodule
Multinodular goiter
Retrosternal/substernal extension possible in large goiter

2. By Function

Non-toxic / euthyroid → Normal T3/T4 and TSH
Toxic / hyperthyroid → Increased T3/T4, decreased TSH
Hypothyroid → Decreased T3/T4, increased TSH in primary hypothyroidism

Benign Nodules and Adenoma

Most thyroid nodules are benign
Follicular adenoma: Benign encapsulated tumor of follicular origin
Can be non-functioning or autonomous/hot
Toxic adenoma → Autonomous hormone production → Low TSH + high T3/T4
Important: Follicular adenoma vs carcinoma cannot be reliably distinguished by cytology alone if capsular/vascular invasion is the question

II. Clinical Features and Diagnosis

Clinical Features

1. Local / Compressive Symptoms

Visible neck swelling, cosmetic concern
Dyspnea, stridor or orthopnea → Tracheal compression/deviation
Dysphagia → Esophageal compression
Voice change/hoarseness → Recurrent laryngeal nerve involvement; malignancy must be considered
Neck pressure, choking sensation, retrosternal extension
Pemberton sign → Facial congestion/dyspnea when arms raised; thoracic inlet compression

2. Hyperthyroidism

Tachycardia, palpitations
Systolic hypertension, widened pulse pressure
Atrial fibrillation, other arrhythmias
Increased intestinal motility, diarrhea
Heat intolerance, sweating, tremor
Weight loss despite increased appetite
Fatigue, proximal muscle weakness
Anxiety, irritability, depression, insomnia
Exophthalmos/orbitopathy → Graves-Basedow disease

3. Hypothyroidism

Bradycardia
Diastolic hypertension
Constipation
Cold intolerance, cold/dry skin
Weight gain, decreased appetite
Muscle cramps, stiffness, fatigue
Depression, cognitive slowing/dementia-like symptoms
Menstrual disturbance, infertility

Physical Examination

Inspect neck from front and side
Ask patient to swallow → Thyroid mass moves with swallowing
Palpate from behind patient with neck slightly flexed
Assess nodule/goiter

Size, side, diffuse vs nodular
Consistency → Soft, firm, hard
Tenderness → Thyroiditis/hemorrhage
Mobility/fixation
Cervical lymph nodes
Tracheal deviation
Voice quality before operation

Laboratory Diagnosis

TSH → First screening test in most thyroid nodules/goiter
Free T4 and T3 if TSH abnormal or thyrotoxicosis suspected
Hyperthyroidism → Low TSH + high free T4/T3
Hypothyroidism → High TSH + low free T4 in primary hypothyroidism
Thyroid autoantibodies

Graves-Basedow disease → TSH receptor antibodies / TRAb / TSI / TSAb
Hashimoto thyroiditis → Anti-thyroid peroxidase Ab (anti-TPO), anti-thyroglobulin Ab (anti-TG)

Preoperative labs → Calcium, renal function, CBC, coagulation if indicated

Imaging and Cytology

Ultrasound

First-line morphology test for thyroid gland and cervical lymph nodes
Distinguishes solid, cystic and mixed nodules
Assesses malignancy risk features

Hypoechogenicity
Irregular margins
Microcalcifications
Taller-than-wide shape
Extrathyroidal extension
Suspicious cervical lymph nodes

Suspicious or size-threshold nodule → US-guided FNAB/FNA
Benign FNA → Follow-up US depending on risk/size/growth

Scintigraphy

Indication → Low TSH / suspected autonomous function
Diffuse homogeneous uptake → Graves-Basedow disease or diffuse hyperactivity
Hot nodule → Autonomous/toxic adenoma; malignancy risk low but not zero
Cold nodule → Non-secreting tissue, cyst or tumor → Needs US risk assessment and often FNAB

CT / MRI

Not routine for simple nodules
Use if retrosternal goiter, airway compression, esophageal compression, mediastinal extension, difficult reoperation or invasive suspicion
CT with iodine contrast can worsen hyperthyroidism and interferes with later radioiodine therapy

III. Main Benign Thyroid Diseases

Diffuse Nontoxic / Simple Goiter

Usually euthyroid
Causes → Iodine deficiency, genetic predisposition, goitrogens
Symptoms → Visible neck enlargement; compression only if large
Treatment

Observation if small, benign and asymptomatic
Iodine supplementation if deficiency
Levothyroxine suppression is less used today; risk of iatrogenic hyperthyroidism, AF and osteoporosis
Surgery if compressive, very large, cosmetic problem or malignancy cannot be excluded

Multinodular Goiter

Multiple nodules, often asymmetric thyroid enlargement
Can be euthyroid, hypothyroid or toxic
Risk → Retrosternal extension, tracheal compression, difficult intubation, occult carcinoma in a nodule
Treatment

Observation for small/asymptomatic benign disease
Surgery if compression, suspicious nodule, large/retrosternal goiter, cosmetic reason or patient preference
Radioiodine in selected toxic multinodular goiter, especially poor surgical candidates without compression/suspicion

Graves-Basedow Disease

Autoimmune hyperthyroidism due to TSH receptor stimulating antibodies
Diffuse toxic goiter
Eye signs → Exophthalmos/orbitopathy, lid lag; not present in toxic adenoma
Treatment options

Medical → Methimazole/carbimazole; PTU mainly first trimester pregnancy or thyroid storm context
Radioiodine I-131 → Definitive treatment in many adults
Total thyroidectomy → Large goiter/compression, suspicious nodule, severe active orbitopathy where radioiodine unsuitable, relapse/failure/intolerance of drugs, patient preference, pregnancy special cases

Before surgery → Make patient euthyroid with antithyroid drugs ± beta-blocker
Potassium iodide/Lugol solution preoperatively may reduce gland vascularity in selected Graves surgery

Toxic Multinodular Goiter / Toxic Adenoma

Autonomously functioning nodule(s) → Hyperthyroidism
No Graves orbitopathy
Antithyroid drugs control hormone excess but usually do not cure autonomy
Definitive treatment → Radioiodine or surgery
Surgery preferred if large goiter, compression, suspicious nodule, need rapid control or patient preference
Toxic adenoma → Hemithyroidectomy/lobectomy possible if unilateral solitary lesion

Hashimoto Thyroiditis

Chronic lymphocytic autoimmune thyroiditis
Common cause of hypothyroidism in iodine-sufficient regions
Anti-TPO ± anti-TG positive
Clinical → Firm painless goiter, hypothyroid symptoms; sometimes transient hyperthyroid phase
Treatment → Levothyroxine replacement if hypothyroid
Surgery is rare → Compression, suspicious nodule/lymphoma/cancer concern or severe cosmetic issue

Subacute Thyroiditis / De Quervain Thyroiditis

Post-viral granulomatous thyroiditis
Painful tender thyroid, fever/malaise, elevated ESR/CRP
Transient hyperthyroid phase → Then possible hypothyroid phase → Usually recovery
Treatment → NSAIDs; corticosteroids if severe pain/inflammation
Beta-blocker for hyperthyroid symptoms; antithyroid drugs do not help because hormone release is from inflammation, not overproduction
Surgery is not routine

Postpartum / Silent / Painless Thyroiditis

Autoimmune-related, usually transient
Painless goiter or mild enlargement possible
Hyperthyroid phase followed by hypothyroid phase
Treatment → Usually observation, beta-blocker for symptoms, levothyroxine if significant/prolonged hypothyroidism

IV. Treatment and Surgical Consequences

Indications for Surgery in Benign Thyroid Disease

Compression syndrome → Dyspnea, dysphagia, stridor, tracheal deviation/compression
Large goiter/nodule, especially > 3-4 cm if symptomatic, growing or diagnostically uncertain
Retrosternal/substernal goiter
Suspicion of malignancy or indeterminate/suspicious FNA
Hyperfunctioning nodule/toxic adenoma if surgery preferred or radioiodine unsuitable
Toxic multinodular goiter with compression/large size/suspicion
Graves disease → Large goiter, relapse/intolerance of drugs, radioiodine contraindicated/undesired, severe orbitopathy context, suspicious nodule
Cosmetic reason or patient preference after counseling

Contraindications / Relative Contraindications

Severe uncontrolled comorbidities or high anesthesia risk
Uncontrolled thyrotoxicosis → Risk of thyroid storm; make euthyroid first if possible
Pregnancy → Surgery only if clearly indicated; second trimester preferred if unavoidable
Locally invasive malignant disease → Not benign thyroid surgery; needs oncological planning

Operations

Lobectomy / hemithyroidectomy → Solitary benign nodule, toxic adenoma, indeterminate unilateral nodule
Near-total/total thyroidectomy → Graves disease, multinodular bilateral disease, large compressive goiter, recurrent goiter, malignancy suspicion depending on case
Subtotal thyroidectomy → Older operation; less common now because recurrence risk and reoperation difficulty
Incision → Kocher collar incision: transverse lower cervical incision above suprasternal notch

Perioperative Preparation

Preoperative laryngoscopy if voice change, previous neck surgery or cancer suspicion
Make hyperthyroid patients euthyroid → Antithyroid drugs ± beta-blocker
Correct severe hypothyroidism before elective surgery if possible
Check calcium/vitamin D status in high-risk patients
Plan difficult airway if large/retrosternal goiter or tracheal compression

Medical / Non-Surgical Treatment

Treatment	Indication	Key point
Observation + US follow-up	Small benign asymptomatic nodule/goiter	Repeat US if growth/risk features
Iodine supplementation	Iodine deficiency goiter	Avoid excess iodine in autonomous nodules
Levothyroxine	Hypothyroidism/Hashimoto	Suppression for benign euthyroid goiter is less favored today
Antithyroid drugs Methimazole/carbimazole, PTU	Graves, temporary control of toxic nodular disease	Monitor agranulocytosis/liver toxicity; PTU special indications
Beta-blocker	Symptomatic hyperthyroidism	Controls tachycardia/tremor; does not stop hormone production
Radioactive iodine I-131	Graves, toxic multinodular goiter, toxic adenoma	Contraindicated in pregnancy/breastfeeding; avoid/consider carefully in active orbitopathy and compression/suspicion
NSAID/steroid	Subacute thyroiditis	Pain/inflammation control; not antithyroid drug disease

Complications of Thyroidectomy

Bleeding / neck hematoma → Airway compression; emergency wound opening may be lifesaving
Recurrent laryngeal nerve palsy → Hoarseness, weak voice, aspiration/choking; bilateral palsy → airway obstruction
External branch of superior laryngeal nerve injury → Loss of high-pitched voice, voice fatigue
Hypoparathyroidism → Hypocalcemia, paresthesia, tetany; usually after total thyroidectomy
Thyroid storm if hyperthyroid patient inadequately prepared
Hypothyroidism → Lifelong levothyroxine after total thyroidectomy
Wound infection, seroma, hypertrophic scar/keloid

Exam focus: Classify goiter by morphology and function; diagnose with examination, TSH/T3/T4, antibodies, US, scintigraphy and FNAB. Know benign nodules, toxic adenoma, Graves disease, multinodular goiter, Hashimoto and de Quervain thyroiditis. Surgery is for compression, large/growing/suspicious nodules, toxic disease when appropriate, failure/contraindication of other therapy or patient preference. Main complications: bleeding airway emergency, RLN palsy and hypocalcemia.