2021-09-22 10:38:01
Papillary Carcinoma of Thyroid
• Accounts for 80% of all thyroid malignancies in iodine-sufficient areasQ
• MC thyroid cancer in children and individuals exposed to external radiationQ.
• More often in women, 30-40 years.
Pathology
• Grossly: Hard and whitish and remain flat on sectioning with a blade with macroscopic calcification, necrosis, or cystic changes
• MultifocalityQ is common (up to 85% of cases) on microscopic examination.
• Multifocality is associated with an increased risk of cervical nodal metastasesQ, rarely invade adjacent structures
such as the trachea, esophagus, and RLNs.
• Rarely encapsulatedQ (PCT are seldom encapsulated)
• Other variants: Tall cellQ, insularQ, columnar, diffuse sclerosing, clear cell, trabecular, and poorly differentiated types; account for
about 1%; associated with a worse prognosis.
Histological characteristics of Papillary Carcinoma Thyroid
• Papillary projectionsQ: PTC contains branching papillae of cuboidal epithelial cells
• Orphan Annie eye nuclei:
₋ The nuclei contain finely dispersed chromatin, which imparts an optically clear or empty appearance, giving
rise to term ground glass or Orphan Annie eye nucleiQ.
₋ Invaginations of cytoplasm in cross-sections: Intranuclear inclusionsQ (pseudo-inclusion) or intranuclear
groovesQ.
₋ Diagnosis of PTC is based on these nuclear characteristicsQ even in the absence of papillary structures.
• Psammoma bodiesQ: Microscopic, calcified deposits representing clumps of sloughed cells
Clinical Features
• Most patients are euthyroid and present with a slow-growing painless massQ in the neck.
• Dysphagia, dyspnea and dysphonia are associated with locally advanced invasive disease.
• Lymph node metastases are commonQ, especially in children and young adults, and may be the presenting complaint.
• “Lateral aberrant thyroid” almost always denotes a cervical lymph node that has been invaded by metastatic
cancerQ.
• Distant metastases are uncommon at initial presentation, but may ultimately develop in up to 20% of patients.
• The MC sites of metastasis: LungsQ >bone >liver >brain.
Diagnosis
• Diagnosis is established by FNAC of the thyroid mass or lymph nodeQ.
• Once thyroid cancer is diagnosed on FNAC, a complete neck ultrasound to evaluate the contralateral lobe and for LN metastases
in the central and lateral neck compartments.
Treatment Total or near-total thyroidectomyQ
• During thyroidectomy, enlarged central neck nodes should be removedQ.
• Biopsy-proven lymph node metastases detected clinically or by imaging in the lateral neck in patients with papillary carcinoma
are managed with modified radical neck dissection.
Prognosis
• PTC have an excellent prognosis with a >95% 10-year survival rateQ.
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