Thyroid Nodules Flashcards
Ms AM, 28, presents to GP with 6/12 Hx of tiredness, otherwise well
No significant PHx
FHx: sister with hypothyroidism
O/E: HR 76, BP 125/75, not clinically anaemic, no abnormalities in the thyroid
Ix?
FBE
Iron studies
TFTs
Ms AM, 28, presents to GP with 6/12 Hx of tiredness, otherwise well
No significant PHx
FHx: sister with hypothyroidism
O/E: HR 76, BP 125/75, not clinically anaemic, no abnormalities in the thyroid
FBE: Hb 135, no abnormalities
Iron studies normal
TSH: 5.35 (N 0.5-5.0), T4 19.1 (N 9.5-19.0), T3 4.5 (N 3.5-6.0)
What further Ix are indicated?
Repeat TFTs (mildly elevated TSH, T4 at upper end of normal)
Anti-thyroid Abs should be ordered
Consider thyroid U/S
Ms AM, 28, presents to GP with 6/12 Hx of tiredness, otherwise well
No significant PHx
FHx: sister with hypothyroidism
O/E: HR 76, BP 125/75, not clinically anaemic, no abnormalities in the thyroid
FBE: Hb 135, no abnormalities
Iron studies normal
TSH: 5.35 (N 0.5-5.0), T4 19.1 (N 9.5-19.0), T3 4.5 (N 3.5-6.0)
Thyroid U/S: L lobe 55x18x15mm, R lobe 45x16x13mm, solitary 18mm nodule in upper pole of L lobe, no calcification or suspicious features noted
Next step?
FNA (should be U/S-guided as this produces lower rates of non-diagnostic and FN cytology)
Indications for FNA of thyroid nodules
Solid nodules at least 10mm in size
Spongey nodules at least 20mm in size
Suspicious U/S features: hypoechoic, microcalcification, increased vascularity, infiltrative margins, absent halo, taller than wide
FHx of thyroid cancer
Hx of head and neck irradiation or exposure to ionising radiation (esp in childhood or adolescence)
Rapid growth of nodule, hoarseness and associated lymphadenopathy
List 6 U/S features of a thyroid nodule which may be suspicious for malignancy
Hypoechoic
Microcalcification
Increased vascularity
Infiltrative margins
Absent halo
Taller than wide
Outline the Bethesda classification for thyroid FNA results
1) Non-diagnostic
2) Benign
3) Follicular lesion or atypia of undetermined significant (5-10% are malignant)
4) Follicular neoplasm (20-30% are malignant)
5) Suspicious for malignancy (50-75% risk of malignancy)
6) Malignant
How should thyroid nodules be managed according to the FNA result?
What do Ms AM’s cytology results show?
Highly cellular sheets of enlarged atypical epithelial cells with oval nuclei and moderate amounts of pale cytoplasma
Numerous papillary structures with fibrovascular cores are present
Frequent nuclear grooves and intranuclear cytoplasmic pseudoinclusions are seen
Features are consistent with thyroid papillary carcinoma
Ms AM is diagnosed with papillary carcinoma of the thyroid following FNA sampling of suspicious lesion in L upper pole
Next steps?
Preoperative neck U/S to assess central and lateral neck compartment LNs
U/S-guided FNA of sonographically suspicious LNs (send for cytology, measure thyroglobulin levels in needle washout)
Routine preoperative use of other imaging modalities (e.g. CT, MRI, PET) is NOT recommended
Ms AM is diagnosed with papillary carcinoma of the thyroid following FNA sampling of suspicious lesion in L upper pole
Preoperative neck U/S does not reveal any suspicious cervical LNs
What are the surgical options available to treat this thyroid cancer? What are the indications for each?
Total thyroidectomy: for thyroid cancer >1cm
Hemithyroidectomy: may be sufficiecnt for small (less than 1cm), low risk, unifocal, intrathyroidal PTC in the absence of PHx of head and neck cancers, FHx of thyroid cancer, or clinically obvious cervical LN metastases
Outline 5 arguments for total thyroidectomy in thyroid cancer patients
PTC often multifocal and bilateral
RAI ablation of thyroid bed remnant and treatment of metastatic disease is facilitated by resection of as much thyroid tissue as possible
Measurements of serum thyroglobulin as tumour marker is facilitated by removal of nearly all normal thyroid tissue
Prevention of recurrence in contralateral lobe
Avoids U/S identified non-specific abnormalities in the remaining contralateral lobe during follow-up that is a source of concern to both clinician and patient
Outline 2 arguments against total thyroidectomy in thyroid cancer
Absence of survival benefit with more extensive surgery
Fewer complications with unilateral surgery
What is the role of LN dissection in thyroid cancer?
Therapeutic central neck dissection for clinically involved central or lateral LNs should accompany total thyroidectomy
May be performed prophylactically in patients with PTC with clinically uninvolved central neck LNs, esp for advanced tumours (i.e. at least 4cm)
Total thyroidectomy WITHOUT prophylactic central neck dissection may be appropriate for small (less than 4cm), noninvasive, clinically node-negative PTCs and most follicular cancers
Therapeutic lateral neck compartmental dissection should be performed where there is biopsy-proven metastatic lateral cervical LN involvement
What 2 adjunctive treatments are frequently used following surgery for thyroid cancer?
Radioactive iodine remnant ablation (give recombinant human TSH i.e. Thyrogen prior to RIA to prevent thyroxine withdrawal and clinical hypothyroidism)
Thyroid hormone suppression therapy: aim for TSH below 0.1mU/L for high-risk and intermediate-risk cancers, and 0.1-0.5mU/L for low-risk cancers
What long term FU is indicated for patients with thyroid cancer?
Annual clinical examination
Thyroid bed/neck U/S at 1 year, then ongoing frequency based on risk
Annual serum thyroglobulin estimation + thyroglobulin Abs
Mr WT, 55, presents to GP with vague fullness in neck and lump on L side of neck; first noticed when shaving a week ago
No significant co-morbidities
O/E: HR 88 reg, BP 125/75, clinically euthyroid, diffusely mildly enlarged and nodular thyroid, with 3cm nodule arising from L lower pole
Further info on Hx and examination?
FHx: ask about pressure Sx (fullness in throat, swallowing or breathing difficulty, pain in throat), voice change (e.g. hoarseness)
O/E: deviation of trachea, retrosternal extension (dullness to percussion), thoracic inlet obstruction (Pemberton’s sign), lymphadenopathy
Mr WT, 55, presents to GP with vague fullness in neck and lump on L side of neck; first noticed when shaving a week ago
No significant co-morbidities
O/E: HR 88 reg, BP 125/75, clinically euthyroid, diffusely mildly enlarged and nodular thyroid, with 3cm nodule arising from L lower pole
Ix?
TFTs
Thyroid U/S
Mr WT, 55, presents to GP with vague fullness in neck and lump on L side of neck; first noticed when shaving a week ago
No significant co-morbidities
O/E: HR 88 reg, BP 125/75, clinically euthyroid, diffusely mildly enlarged and nodular thyroid, with 3cm nodule arising from L lower pole
TFT: TSH 2.75, T4 17.6, T3 5.5
U/S: R lobe measures 60x25x20mm, L lobe measures 65x30x25mm, and there are multiple solid nodules within the thyroid gland bilaterally - largest on R side is 15mm in the upper pole, largest on L side is 30mm in lower pole, remainder are all sub-cm and there are no concerning features in any of the nodules
Should any of these nodules undergo FNA?
Nodules with suspicious sonographic appearance should undergo FNA preferentially
If none have a suspicious appearance and multiple sonographically similar nodules are present, risk of malignancy is low and it is reasonable to aspirate the largest nodules only and observe the others with serial U/S examinations
Radionuclide scanning can also be considered in patients with multiple nodules, with FNA being reserved for those nodules that are shown to be hypofunctioning
Mr WT, 55, presents to GP with vague fullness in neck and lump on L side of neck; first noticed when shaving a week ago
No significant co-morbidities
O/E: HR 88 reg, BP 125/75, clinically euthyroid, diffusely mildly enlarged and nodular thyroid, with 3cm nodule arising from L lower pole
TFT: TSH 2.75, T4 17.6, T3 5.5
U/S: R lobe measures 60x25x20mm, L lobe measures 65x30x25mm, and there are multiple solid nodules within the thyroid gland bilaterally - largest on R side is 15mm in the upper pole, largest on L side is 30mm in lower pole, remainder are all sub-cm and there are no concerning features in any of the nodules
Dominant nodule on each side undergoes U/S-guided FNA
Cytology report: appearance is the same on both sides, there is abundant colloid and scant follicular cells which are small and uniform with a central nucleus, with the cells grouped into follicles
Conclusion?
Both nodules are colloid nodules
Mr WT, 55, presents to GP with vague fullness in neck and lump on L side of neck; first noticed when shaving a week ago
Diagnosed with colloid nodules (i.e. MNG) following FNA
What are the indications for surgery in MNG?
Evidence of malignancy
Increasing size of dominant nodule(s)
Symptomatic (pressure Sx, hoarseness)
Retrosternal extension (relative indication: take into account the patient’s age, comorbidities and ability to remove the goitre through the neck - usually possible but does depend on extent of retrosternal extension)
What follow-up is indicated for patients with MNG?
Annual clinical examination and U/S
Nodules increasing in size (one definition is >50% increase in volume or >20% increase in at least two nodule dimensions in solid nodules or the solid componant of mixed-cystic nodules) should undergo repeat FNA
If nodules have remained stable for 1-2 years, interval before next clinical examination and U/S may be longer (e.g. 3-5 years)
Mr PW, 35, presents to his GP with sore throat and productive cough for 3/7
O/E: red throat, slightly enlarged submandibular LNs and lump on L side of neck which moves upwards with swallowing
GP suspects this is a thyroid nodule
Mr PW has also had insomnia for last year; for last 3/12 he has noticed his heart beating “strongly” on occasions when he has been resting
Weight is stable
Ix?
TFTs
Thyroid U/S
Mr PW, 35, presents to his GP with sore throat and productive cough for 3/7
O/E: red throat, slightly enlarged submandibular LNs and lump on L side of neck which moves upwards with swallowing
GP suspects this is a thyroid nodule
Mr PW has also had insomnia for last year; for last 3/12 he has noticed his heart beating “strongly” on occasions when he has been resting
Weight is stable
TFT: TSH 0.01, T4 23.6, T3 7.2
Thyroid U/S: R lobe measures 45x18x16mm, L lobe measures 55x25x20mm, solitary 29mm nodule in mid part of L lobe with increased vascularity, no other abnormal findings
DDx?
Ix?
Thyroid nodule autonomously producing thyroid hormone (“toxic” nodule)
Grave’s disease with incidental nodule
Sub-acute thyroiditis (unlikely; has not had neck pain or general malaise)
Ix: nuclear thyroid scan to assess function of thyroid overall as well as function of nodule
Mr PW, 35, presents to his GP with sore throat and productive cough for 3/7
O/E: red throat, slightly enlarged submandibular LNs and lump on L side of neck which moves upwards with swallowing
GP suspects this is a thyroid nodule
Mr PW has also had insomnia for last year; for last 3/12 he has noticed his heart beating “strongly” on occasions when he has been resting
Weight is stable
TFT: TSH 0.01, T4 23.6, T3 7.2
Thyroid U/S: R lobe measures 45x18x16mm, L lobe measures 55x25x20mm, solitary 29mm nodule in mid part of L lobe with increased vascularity, no other abnormal findings
Results of nuclear thyroid scan attached
Interpretation?
Increased uptake in mid part of L lobe (corresponding to nodule seen on U/S) with reduced uptake in remaining thyroid (this is due to suppression of TSH by the autonomous production of thyroid hormone from the nodule, meaning that the rest of the gland is not being stimulated and therefore does not take up tracer on a nuclear scan)
Findings are consistent with hyperfunctioning nodule in L lobe of thyroid with suppression of remainder of gland
