Improvement in the Detection of Cystic Metastatic Papillary Thyroid Carcinoma by Measurement of Thyroglobulin in Aspirated Fluid

Table 1

Correlations between the final diagnosis and the Tg-FNA values.

Final diagnosis	Case number	Tg-FNA values (ng/mL); range/median
Metastatic PTCs	40	0.64–500+; 500+
Reactive lymphadenitis	5	2.10–5.74; 4.43
Metastases from extrathyroidal malignancies	15	0.10–21.15; 1.38
Cervical original benign lesions	15	0.09–500+; 2.04
Branchial cleft cysts	2	0.09–0.12; 0.10
Thyroglossal cysts	3	5.40–500+; 6.22
Lymphangiomas	4	0.35–3.20; 1.48
Schwannomas	2	2.04–50.20; 26.12
Cystic lesions of the salivary gland	4	0.10–2.54; 1.29

One case of metastatic PTC was diagnosed histologically as metastatic thyroid carcinoma where the tumor was mainly composed of squamous carcinoma with a small component of papillary carcinoma. The Tg-FNA value of this case was 0.64 ng/mL and was the lowest of the metastatic PTCs.
All 5 cases had a history of thyroidectomy for thyroid papillary carcinoma. These negative lymph nodes were followed up by sonography for at least 12 months and showed a decrease in size.