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  • Thyroid cancer is the most common endocrine neoplasm worldwide, representing 1.7% of new cancer diagnoses and 0.5% of cancer deaths each year (Baldini et al.)
  • The majority of thyroid cancers are primary (originating within the gland itself), are well-differentiated, and are derived from follicular epithelial cells
  • Papillary thyroid cancer is the most common subtype

70-80% of all thyroid cancers

Peak incidence in women of child-bearing age

Generally indolent behavior, excellent prognosis with total thyroidectomy

30-90% of patients exhibit recurrent or persistent metastasis to the cervical lymph nodes (Torres et al.) and 20% of cases present with occult cancer that is only identifiable in the nodes without evidence of a primary tumor (Cunha et al.)

It is important to detect local lymph node involvement in order to determine appropriate surgical management, clinical follow-up, and prognosis (Baldini et al.)

  • Evaluation for lymph node involvement

Gold standard: fine needle aspiration + cytology (FNAC)

Diagnostic pitfalls:

Cystic change – very common in head and neck cancers, especially papillary thyroid cancer (Ustun et al.)


Thyroglobulin wash testing (TgW)

Syringe used for FNAC flushed with normal saline

Tg level in washout fluid measured using chemiluminescent assay

Adding TgW to FNAC increases sensitivity and specificity to nearly 100% (Suh et al.)