MSC - F. Surgery Answers 2025
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oGoitrogens (foods: cassava, cabbage, soy; drugs: thioureas, sulfonamides)
o Environmental toxins: lead, nitrates, organophosphates.
oGenetic factors: dyshormonogenesis (peroxidase defects, impaired iodide trapping).
oAutoimmune element: mild immune dysregulation may enhance growth, not function.
Clinical Picture:
Goiter type: Diffuse or mixed (diffuse-nodular).
Symptoms: Often asymptomatic. If large:
o Local compression: dysphagia, dyspnea, hoarseness.
oCosmetic concerns.
Thyroid function: Usually euthyroid, but subclinical or overt hypothyroidism may occur.
oLabs: ↑ TSH, ↑ T3, ↓ T4/T3 ratio, ↓ urinary iodine.
Diagnosis:
Clinical: Palpable thyroid enlargement (≥Grade II–III).
Imaging: Ultrasound, scintigraphy for structure and nodularity.
Lab: TSH, T3, T4, urinary iodine excretion.
Fine needle aspiration biopsy: for nodular/mixed goiter (rule out malignancy).
Differentiate from: Hashimoto’s thyroiditis, thyroid neoplasm, infiltrative diseases.
Treatment:
Indications: Goiter ≥ Grade II in children, ≥ Grade III in adults.
First-line: Long-term thyroid hormone suppression therapy (L-thyroxine 50–200 µg/day).
oGoal: ↓ TSH → reduce stimulation → shrink goiter.
Other options:
oNSAIDs (e.g., Indomethacin) in mild forms.
oSurgery: for compressive symptoms or nodules with suspicious features.
Prevention:
Mass prophylaxis: Universal iodized salt (≥25 mg potassium iodate/kg).
Group/individual prophylaxis:
oAntistrumin (potassium iodide 1 mg) weekly for:
Children in endemic regions.
Pregnant and lactating women.
Public health monitoring: Regular goiter surveys, iodine status evaluation.
4.Sporadic goiter. Clinical picture, diagnosis, treatment.
Non-toxic enlargement of the thyroid gland occurring outside endemic regions, in the absence of widespread iodine deficiency. Thyroid function is usually normal (euthyroid).
Etiology:
Unlike endemic goiter, sporadic goiter is caused by individual-specific factors, including:
Goitrogenic substances (e.g., cassava, soy, certain drugs like thioureas, sulfonamides, lithium).
GI and liver diseases → impaired iodine absorption/metabolism.
Iodine in poorly bioavailable forms.
Congenital thyroid enzyme deficiencies (dyshormonogenesis), especially:
oDeficient iodide transport, peroxidase activity, organification defects.
Clinical Picture:
Thyroid enlargement: Usually diffuse, sometimes nodular.
Function: Mostly euthyroid, though subclinical or overt hypothyroidism can develop.
Symptoms:
o Often asymptomatic.
o Cosmetic neck swelling.
oLarge goiter may cause compressive symptoms (dysphagia, dyspnea, hoarseness).
Diagnosis:
Clinical exam: Palpable thyroid enlargement.
Thyroid function tests:
o TSH: normal or slightly ↑
oT3/T4: normal (in euthyroid state)
Ultrasound: Evaluate size, texture, nodularity.
Fine needle aspiration biopsy (FNAB): For nodules to rule out malignancy.
Exclude: Autoimmune thyroiditis, neoplasia.
Treatment:
Indications: Cosmetic concern, compression, progressive growth, or thyroid dysfunction.
Medical:
oL-thyroxine suppression therapy (50–150 µg/day) to reduce TSH stimulation.
Surgical: Large nodular goiter or suspicion of cancer.
Radioiodine: Rarely used, more for toxic nodules.
Prevention:
No mass prophylaxis needed (non-endemic regions).
Avoid goitrogens, especially in susceptible individuals.
Ensure adequate iodine intake (WHO: 150 µg/day for adults).
5.Nodular goiter. Clinical picture, diagnosis, treatment.
A thyroid enlargement characterized by one or more palpable nodules, often due to long-standing thyroid hyperplasia and degeneration. It is the most common thyroid disorder in adults, especially women >35 years.
Etiology:
Often evolves from a longstanding diffuse goiter (e.g., untreated endemic goiter).
May involve:
o Colloid accumulation
o Cystic degeneration
o Hemorrhage
oFibrosis and calcification
TSH stimulation, oxidative stress, and local growth factors contribute.
Clinical Picture:
Symptoms:
Most are asymptomatic
Neck swelling is the most common complaint
Pressure symptoms (when large):
o Dysphagia (esophageal compression)
o Dyspnea, stridor (tracheal compression)
oJugular venous distention
Acute pain/swelling: Sudden hemorrhage into a cyst—surgical emergency
Rarely:
oRecurrent laryngeal nerve palsy
o Horner’s syndrome → Suggests malignancy
Signs:
Swelling moves with swallowing
On palpation:
o Irregular, nodular surface
o Multiple nodules usually, but may present as solitary nodule
oSoft to firm; softer than Graves’ gland
May be retrosternal in large cases
Complications:
Secondary thyrotoxicosis (autonomous hot nodules)
Compressive symptoms
Thyroid carcinoma (~5–10%)
Diagnosis:
Basic Labs:
TSH, Free T4, T3: Usually euthyroid; may show mild thyrotoxicosis
Anti-TPO/anti-Tg antibodies: To exclude thyroiditis
Imaging & Tests:
1.Ultrasound: First-line; identifies number, size, structure of nodules
2.FNAC: Key to exclude malignancy
3.Thyroid scan (radioisotope):
o Cold nodule = suspicious
oHot nodule = usually benign
4.X-ray neck/chest: Tracheal deviation, retrosternal extension, calcification
5.Barium swallow: If dysphagia present
6.CT/MRI: Rarely, for large retrosternal or substernal goiters
Treatment:
Medical:
L-thyroxine suppression therapy:
o 50% show reduction in size with 120–180 mcg/day
oHowever, nodularity persists
Goal: Suppress TSH to halt growth stimulus
Surgical:
Definitive treatment
Indications:
o Large goiter
o Suspicion of malignancy
o Pressure symptoms
oCosmetic concern
Procedures:
oTotal or subtotal thyroidectomy
oLobectomy if confined to one lobe
Always followed by:
oL-thyroxine 100 mcg/day to suppress TSH and prevent recurrence
Follow-up:
Thyroid function tests
Neck ultrasound (if nodules remain)
Lifelong L-thyroxine therapy postoperatively
6.Diffuse toxic goiter. Clinical picture, conservative and surgical treatment.
Synonym: Graves’ disease
Etiology: Autoimmune thyroid disorder caused by thyroid-stimulating immunoglobulins (TSI) that bind to the TSH receptor, leading to:
Thyroid hyperplasia
Increased thyroid hormone synthesis and secretion (T3/T4)
Diffuse gland enlargement
Pathophysiology
Strong association with HLA-B8, HLA-DR3
More common in women (female:male = 7:1)
Typical onset: 20–40 years
Clinical Features
1.Hypermetabolic Symptoms (due to ↑ T3/T4):
Weight loss despite increased appetite
Heat intolerance, sweating
Warm, moist skin
Low-grade fever
2.Cardiovascular:
Tachycardia, palpitations
Atrial fibrillation (especially in elderly)
High systolic / low diastolic BP
Development of thyrotoxic heart disease
3.Neurological:
Anxiety, tremors, restlessness
Insomnia
Reflexes exaggerated
Proximal muscle weakness
4.Gastrointestinal:
Frequent defecation/diarrhea
5.Ocular (Graves’ ophthalmopathy):
Exophthalmos
Lid lag and stare
Periorbital edema
Diplopia (due to extraocular muscle involvement)
Rare: optic neuropathy
6.Reproductive:
Menstrual irregularities
Infertility
Gynecomastia (in males)
7.Goiter Signs:
Diffuse, symmetrical thyroid enlargement
Bruit on auscultation (↑ vascularity)
Moves on swallowing
Severity Classification |
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Grade |
Pulse |
Weight loss |
Complications |
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Mild |
<100 bpm |
10–15% body |
None |
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weight |
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100–120 |
15–25% loss |
Mild symptoms |
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Moderate bpm |
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Severe |
>120 bpm |
>25–50% loss |
Thyrotoxic heart, hepatitis, |
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encephalopathy |
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Diagnosis
1. Thyroid Function Tests:
o ↓ TSH
o ↑ Free T4 and/or T3
oT3 toxicosis possible
2.Thyroid Autoantibodies:
oPositive TSI (Thyroid-stimulating immunoglobulins)
oAnti-TPO and Anti-Tg antibodies may also be elevated
3.Ultrasound:
oDiffuse enlargement, increased vascularity
4.Radioactive Iodine Uptake Scan (RAIU): o Diffuse, homogeneous uptake
5.ECG/Echo: Rule out cardiac complications
Management
I. Conservative (Medical) Treatment
Goal: Achieve euthyroid state
A.Antithyroid Drugs:
Methimazole (preferred): 10–30 mg/day
Propylthiouracil (PTU): preferred in 1st trimester of pregnancy or thyroid storm
B.Beta-blockers (Symptomatic control):
Propranolol 40–80 mg TID or
Metoprolol, Atenolol
C.Corticosteroids:
In severe cases with ophthalmopathy or thyroid storm
↓ Peripheral conversion of T4 to T3
D.Sedatives/Tranquilizers:
To reduce sympathetic overdrive
E.Plasmapheresis (in severe or resistant cases):
↓ Hormone levels rapidly
Helpful in thyrotoxic crisis or drug-resistant cases
II.Indications for Surgery (Subtotal or Near-total Thyroidectomy)
1. Failed medical therapy after 1.5–2 years