Neck mass, goitre, thyroid states and thyroid cancer Flashcards
Approach to Neck Mass
- Examination of neck mass
- Determining thyroid state
- Assessing complications of disease and treatment
Examination technique of neck mass
(Look, Feel, Move, Percussion, Auscultation)
A. Inspection - location, size and shape
1. Look from the front and the side
(normal: from side contour from cricoid cartilage to suprasternal notch is smooth)
(abnormal: any prominence beyond the contour)
Borders of thyroid gland:
- Horizontal: left to right sternocleidomastoid muscle
- Vertical: suprasternal notch to thyroid cartilage
B. Feel - palpate from behind
2. Positioning:
- Slightly flexed to relax strap muscles
- Then slightly extended to stretch overlying tissues
3. Start from thyroid isthmus (below cricoid cartilage): usually not palpable unless enlarged
4. Palpate from medial to lateral both sides
(Lobes extend laterally, posteriorly to sternocleidomastoid muscles)
5. Feel for pyramidal lobe superior to isthmus
6. Cervical lymphadenoapthy
Tips on palpating thyroid lobes:
- Place fingertip medial to sternocleidomastoid muscle, then another hand to palpate for thyroid lobes
- Avoid compressing thyroid between sternocleidomastoid and trachea
- Avoid palpating too laterally
C. Movement - take a sip of water and swallow
7. Swallowing - thyroid moves with swallowing
(thyroid enclosed in pretracheal fascia with posteromedial ligament of Berry)
8. Tongue protrusion - thyroglossal cyst moves with protrusion
D. Percussion
9. Percuss till sternum to determine extension of retrosternal goitre (dullness)
(Not needed if inferior border of thyroid gland can be clearly felt)
E. Auscultation over upper poles
10. Thrills and bruit (superior thyroid artery branches from ECA)
F. Pemberton’s manoeuver
(Not recommended to do during PACES - see subsequent card)
G. Commenting on thyroid states
11. Euthyroid, hyperthyroid or hypothyroid
(heart rate, any tremors, eye signs, reflexes)
Describing thyroid gland
- Description of thyroid gland
- Site: unilateral or bilateral
- Number of nodules
- Shape: smooth, irregular, nodular, or diffuse
- Border and extent
- Consistency: soft, firm, hard - Tenderness - thyroiditis
- Mobility - Fixed or mobile
- Tracheal deviation - in unilateral enlargement
- Lymphadenopathy
- Carotid artery bruit
What are the differentials for tender thyroid gland?
How about non-tender thyroid gland?
Tender thyroid gland
Usually thyroiditis (not all)
1. Subacute/granulomatous (De Quervain)
2. Infectious and abscess formation
3. Traumatic
4. Radiation (following RAI)
Non-tender thyroid gland
1. Postpartum thyroiditis
2. Riedel’s thyroiditis (firm hard rock, fixed, painless due to fibrosis)
3. Graves’ disease (rarely painful)
4. Hashimoto’s thyroiditis (rarely painful)
Pemberton’s manoeuver
- Hold arms above head for 60 seconds - forces thyroid into thoracic inlet
Positive if:
1. Neck veins become distended or
2. Facial plethora, cyanosis, dyspnoea, dysphagia
How does bruit occur in Graves’ disease?
Hypertrophy of thyroid gland and accelerated blood flow through tortuous thyroid arteries
Also Means-Lerman scratch sound over precordium (rubbing of hyperdynamic precardium against pleura)
Differential diagnoses of thyroid mass
(Solitary nodule vs multinodular)
Solitary nodule
1. Thyroid adenoma
2. Toxic adenoma (Plummer’s disease)
3. Thyroid cyst
4. Thyroid cancer
5. Single palpable nodule in multinodular goitre
Multinodular or diffuse
1. Single large goitre (iodine deficiency)
2. Physiological goitre (puberty, pregnancy)
3. Graves’ disease (diffuse goitre)
4. Hashimoto’s thyroiditis
5. De Quervain’s thyroiditis (painful goitre)
6. Goitrogens and dyshormonogenesis
Differential diagnoses of neck mass
- Thyroid mass or malignancy
- Thyroglossal cyst - midline, moves on tongue protrusion
- Branchial cleft anomalies (cyst, sinus, fistula)
- Large lymphadenopathy - infection, granulomas (sarcoidosis, tuberculosis), malignancy
- Carotids: carotid body tumour, carotid artery aneurysm
- Jugular vein: thrombosis, haemangioma
- Salivary: sialadenitis, salivary gland tumour
- Shwannoma, neurofibroma, nerve tumours
Differential diagnoses of retrosternal mass
- Retrosternal goitre
- Thymoma
- Lymphoma
- Germ cell tumours (teratoma, seminoma)
- Mediastinal cyst
- Parathyroid mass
History taking of hyperthyroidism vs hypothyroidism
Examination findings of hyperthyroidism vs hypothyroidism
Complications of large goitre
- Dyspnoea, upper airway obstruction
- Dysphagia
- Recurrent laryngeal nerve paralysis - hoarseness
- Horner’s syndrome
- Jugular vein compression and thrombosis
- Cerebrovascular steal syndrome
Possible tests for evaluation of thyroid function and etiologies
- Thyroid function test - TSH, fT4
- Total T4 (tT4)
- Total T3 (tT3) and free T3 (fT3)
- Reverse T3 (RT3)
- Thyroid autoantibodies - anti-TPO, anti-TG, TRAb
- Thyroglobulin (TG)
- Calcitonin
- US thyroid
- RAUI
- Thyroid scan (nuclear scintigraphy)
- FNA and biopsy
What are the significance of TSH
TSH is the primary regulator of thyroid hormone synthesis and secretion.
- Log-linear relationship between TSH and fT4 levels
- Small changes in T4 production results in large changes in TSH - Abnormal TSH appears way before T4 and T3 levels become deranged
- Diurnal pattern - highest TSH late afternoon to evening
- Low TSH -> hyperthyroidism
- High TSH -> hypothyroidism
Thyroid autoantibodies
- Anti-TPO and anti-TG: Hashimoto’s thyroiditis
(anti-TPO more sensitive) - TSH receptor Ab (TRAb) and TSIg: Graves
When is thyroglobulin (TG) measurement useful?
TG - major iodoprotein constituent of thyroid follicles
- Diagnosis of diseases
- Mildy increased in thyroid diseases
- Marked increased in thyroid cancer and destructive thyroiditis (subacute, postpartum, silent) - Monitoring of thyroid cancer
- TG should be undetectable when thyroid cancer treated
- Normal or rising TG suggest residual or metastatic thyroid cancer - NOT USEFUL when anti-TG is positive
- interferes with TG measurement
When is calcitonin measurement useful?
Calcitonin secreted by thyroid parafollicular C cells
- Diagnosis of medullary carcinoma
- Elevated in medullary carcinoma of thyroid and C-cell hyperplasia
Types of thyroid cancer (Dunhill Classification)
Primary
A. Differentiated epithelium
1. Papillary carcinoma (70%)
2. Follicular carcinoma (20%)
B. Undifferentiated
3. Anaplastic carcinoma (1%)
C. Parafollicular cells
4. Medullary (5%)
Secondary
5. Lymphoma (a/w Hashimoto)
6. Metastatic
What are the risk factors/causes of thyroid cancer?
- Head and neck irradiation in childhood
(obsolete treatment between 1910-1960s) - Genetics: familial adenomatous polyposis, Gardner’s syndrome (ret/PTC3 and ret/PTC1 oncogene)
- Endemic goitre and prolonged TSH stimulation
- Autoimmune thyroiditis (Hashimoto’s)
What are the clinical features (symptoms and signs) that are predictive of malignancy?
Clinical symptoms
1. Female > male
2. Progressive thyroid swelling
3. Neck pain radiating to the ears
4. Constitutional symptoms
5. MEN2 syndromes: phaeochromocytoma, hyperparathyroidism, neurofibromatosis
Clinical signs
1. Fixed, hard mass
2. Obstructive symptoms - stridor, facial congestion
3. cervical lymphadenopathy
4. Vocal cord paralysis - hoarseness
Differentiating features of different thyroid cancers
Management of thyroid cancer
- Total thyroidectomy with excision of adjacent involved structures, LN dissection
- Oral radioiodine for metastasis scintigraphy scan
- If positive, large doses of radioiodine given - Suppress TSH production to < 0.1 mU/L by:
- Oral tri-iodothyronine (T3) 60-80ug/day during
follow-up period (can stop quickly – T4 30 days)
- Later oral thyroxine 0.1-0.2 mg/day - Monitoring of recurrence
- Measure serum thyroglobulin, TSH levels
MEN2a syndrome - autosomal dominant with medullary thyroid ca, phaeochromocytoma and primary hyperparathyroidism
MEN2b syndrome - autosomal dominant with medullary thyroid ca, phaeochromocytoma and neurofibromatosis
Genetic testing: RET gene (chromosome 10)
