Thyroid Tumors😍

Thyroid Tumors

1. Benign:
• Follicular adenoma.

2. Malignant:
1. Papillary Ca.
2. Follicular Ca.
3. Medullary Ca.
4. Anaplastic Ca.

3. Lymphoma

• F > M.

Associated Syndromes:

• Medullary:
• MEN 2 → RET.

• Follicular: 
• Cowden syndrome → PTEN
• Werner syndrome → WRN
• Folli (Follicular) Pottan () aged faster (Werner)

• Papillary:
• Familial Adenomatous Polyposis → APC
• Cowden Syndrome → PTEN
• Mnemonic: Papi () is Family (FAP) but Pottan ()

Suspect Malignancy if Nodule has these features:

• Single

• Solitary

• Cold (on scan)

• Present in young male

• Previous history of radiation exposure

Differentiated Thyroid Cancer (DTC) Staging

• (DTC includes: Papillary, Follicular, Hurthle cell ca.)

• Age cut off:
• Age at diagnosis <55 years (Good prognosis).

• T3a: 
• Tumor >4 cm confined to thyroid gland.

• T3b: 
• Strap muscles involvement.

• Anaplastic cancers:
• Previously classified as T4 disease
• Use same 'T' definitions as DTC

Surgical Approach for DTCs

• Hemithyroidectomy:
• Low risk.
• Unilateral DTC b/w 1-4 cm.
• No extrathyroidal extension.

• Total thyroidectomy (TT):
• Radiation induced DTC.
• Familial non-medullary thyroid ca.
• Multifocal B/L DTC.
• Extracapsular extension.

• TT + Central Neck Dissection (CND):
• T3, T4 disease.
• Prophylactic CND.
• Level 6 lymph nodes.

• TT + CND + Modified Radical ND (MRND):
• Other nodes involved.

Post-Operative Management of DTCs

• Traditional:
• Wait 4-6 weeks → ↑TSH (>30 IU/L) → Whole body I¹³¹ scan → Radioiodine ablation (1°).

• New:
• Recombinant TSH → Whole body I¹³¹ scan → Radioiodine ablation (1°).

• Whole body I¹³¹ scan
• If Positive
• Radioiodine ablation (1°):
• F/B: ↓.
• T1/2: 8 days, via β-rays.
• Indications: Residual disease, lymph nodes, metastasis.
• If negative
• Life long follow-up:
• Thyroxine (TSH suppression).
• USG neck & S.Tg (6 monthly).
• Serum thyroglobulin (S.Tg):
• Tumor marker for all DTCs.
• If >2 ng/mL: Suspect recurrence.

Prognostic Indicators of DTCs

• AGES system:
• Age, Histologic Grade, Extrathyroidal invasion, Size.

• AMES system:
• Age, Metastases, Extrathyroidal spread, Size of tumours.

• MACIS (Post-operative score):
• Metastases
• Age
• Completeness of original Sx-resection,
• Extrathyroidal invasion
• Size of original lesion

Papillary Carcinoma Thyroid

• Most common thyroid tumor.

• F > M.

• Excellent prognosis 
  (near 100% survival with total thyroidectomy)

• Risk Factors: 
• Radiation exposure to neck → More aggressive tumour.
• Long standing thyroglossal cyst.
• Genetic: BRAF gene (m/c involved).
• RET/PTC rearrangements
• Hashimoto's thyroiditis

BRAF 600E mutation.



• Associated with Tyrosine Kinase receptor gene mutation

• Spread
• Lymphatic → Level 6/Delphian LN > Hematogenous → Lungs (m/c site).
• Lateral aberrant thyroid:
• Palpable LN d/t mets from PTC
• Thyroid incidentaloma:
• Incidentally detected <1 cm tumor (Follicular variant of PTC).

• Microscopy:
• True papillae 
  (finger-like, containing a fibrovascular core).
• Orphan Annie Eye Nucleus
  (Optically Clear Nucleus): 
• White/clear nuclei
  (artifact, not seen on FNAC).

• Intranuclear inclusions 
• round dots within nucleus
• Intranuclear groove
• Coffee Bean Appearance
• Psammoma bodies (calcifications).

• FNAC: 
• Chewing gum colloid (stretched pinkish colloid).

• Variants:
• Microcarcinoma:
• Tumor measures less than 1 cm.
• Follicular variant:



• Follicular architecture, retains characteristic nuclear features.
• Lindsay tumor/ Solid Encapsulated Follicular Variant (SEFV)
• Follicular variant of papillary
• Same prognosis as PTC
• SCFC - Solid, Capsulated, Follicular Carcinoma/Variant
• Poor Prognosis Variants:
• Tall cell variant:
• Cells tall (length three times width),
• >30% such cells seen.
• Diffuse sclerosing variant.

• Mnemonic: Braf, true papi, orphan annie, coffee, chewing gum
• Papillary → True papi (Tru papillae) offered coffee
• But Orphan annie was a brat and was chewing gum

Anaplastic Carcinoma

• Worst prognosis (survival often only 6 months).

Follicular Thyroid Cancer

• 2nd m/c thyroid cancer.

• F > M.

• 2nd best prognosis.

• Most common mutation:
• RAS mutation.

• Risk factors
• Long-standing multinodular goitre (Rapid ↑size).
• Genetics: PTEN & BAX gene mutations.
• Up-regulation of miRNA 197, 34b.
• Werner Syndrome

• Spread
• Hematogenous: 
• Bones (m/c site).
• May be pulsatile d/t vascularity.
• Lymph node (LN): 
• Level 6.

• Diagnosis:
• Requires invasion assessment → 
1. Capsular invasion, 

2. Angioinvasion (vascular invasion).

• Cannot be diagnosed on FNAC (insufficient tissue for invasion assessment).

• Mx
• FNAC reports Follicular Neoplasm (Thy3) → Hemithyroidectomy.
• F/b frozen section (for diagnostic confirmation).
• Surgical approach & post-op management similar to DTC.

Mnemonic:

• Follicular → flower → Pottan (PTEN) with rashes (RAS) → took a flower () saying its my rna (mirna) → She gave it Back (Bax)

Medullary Thyroid Cancer

• Origin: Parafollicular 'c' cells.
• From ultimobranchial bodies of neural crest.
• Does not take up iodine.

• Genetics: 
• RET gene mutation on chromosome 10.
• Mnemonic: RET 10 MED MEN 2 SIP (MEN 2A→ sipple)

• Etiology: Sporadic > Familial

Associated Syndromes:

• Occurs in MEN 2A and MEN 2B syndromes.
• More aggressive → MEN 2B
• Young patient
• RET gene mutation
• Multifocal

Features

• Thyroid swelling.

• Diarrhea
• Calcitonin and serotonin are responsible

• Aggressive tumors.

Tumor Marker: 

• Calcitonin

• Tumor Marker for calcitonin negative medullary carcinoma
• CEA

• It secretes NSE hormones

Radioiodine uptake

• Negative
• Bcz it is TSH independent

Spread

• Lymphatic (Level 6 LN).

• Hematogenous (m/c Liver).

Microscopy:

• Amyloid rich stroma.

• Amyloid deposition (aCal amyloid): 
• Pink material outside cells.

• Amyloid Confirmation:
• Stains with Congo red → apple-green birefringence under polarizing microscope.

IOC

• FNAC.

Surgical Mx

• Metastases: Vandetinib, Cabozantinib.

• Mnemonic: Madam said Vande () bharath inside a cabin (cabozantidinib)

Note

• Always rule out pheochromocytoma before Sx.

• No role of thyroid scan & radioactive iodine.

Anaplastic Carcinoma

Features

• Presents as a large swelling.

• L/C (Least Common).

• Seen in 5-7th decade of life.

• Worst prognosis

Metastasis

• Lungs (m/c).

Genetic risk factor

• p53 mutation.

C/F

• Rapidly enlarging swelling.

• Hoarseness of voice (RLN involved).

• Stridor (Tracheal compression).

Microscopic Features

• Spindle cell

• Sarcomatoid cells

• Giant cells

Mx

• Restricted to thyroid:
• Aggressive Surgery

• Extrathyroidal spread:
• Palliative mx.
• Tracheal compression:
• Isthmusectomy.

Lymphoma

Epidemiology

• Population: Generally elderly.

Risk Factor

• Hashimoto's thyroiditis.

Type of Lymphoma

• MALToma.

Hurthle Cell Carcinoma

• Earlier considered a variant of FTC.

• Seen in elderly (6-7th decade of life).

• HPE: 
• Oxyphilic Hurthle cell (Mitochondria rich).

• More aggressive than FTC.

• Less radioiodine avid than other DTC.