OBJECTIVE: Measurement of thyroglobulin in the washout of lymph node (LN) fine needle aspirates is recommended in the follow-up of patients with differentiated thyroid cancer (DTC). The significance of low fine needle aspirates thyroglobin (FNATg) levels remains a question, which we addressed. METHOD: Prospective study comparing FNATg with FNA cytology. Exploration of 34 DTC patients (53 cervical LNs), 26 non-thyroidectomized patients with a thyroid-unrelated cervical mass (negative controls) and 13 with 21 thyroid nodules (positive controls). The 12 DTC patients (19 LNs) with a malignant FNA cytology and/or high FNATg level received LN surgery (11 patients) or I(131)-iodine treatment (1 patient) and the outcome measure was pathological or scintigraphic evidence of DTC LN metastasis. RESULTS: All 26 negative controls showed FNATg <1 ng/FNA and all 21 positive controls showed high levels of FNATg (127-210,000 ng/FNA, median 38,000). Among DTC patients in 25 LNs with a benign FNA cytology, FNATg was undetectable in 24 and low in 1 (6 ng/FNA); in 19 LNs with a malignant FNA cytology, FNATg was high in 17 (80-140,000 ng/FNA, median 7174 ng/FNA) and low in 2 (6.6 and 7.1 ng/FNA), which proved to be low Tg immunostaining oncocytic DTC metastasis; in 9 LNs with a non-informative cytology, FNATg was undetectable in 8 but 11,825 ng/FNA in 1, which proved a DTC metastasis. Measurement of FNA albumin demonstrated that contamination of FNA by serum proteins was negligible. CONCLUSION: Low FNATg levels can indicate a DTC metastasis. It cannot be related to clinically relevant levels of serum Tg.
OBJECTIVE: Measurement of thyroglobulin in the washout of lymph node (LN) fine needle aspirates is recommended in the follow-up of patients with differentiated thyroid cancer (DTC). The significance of low fine needle aspirates thyroglobin (FNATg) levels remains a question, which we addressed. METHOD: Prospective study comparing FNATg with FNA cytology. Exploration of 34 DTCpatients (53 cervical LNs), 26 non-thyroidectomized patients with a thyroid-unrelated cervical mass (negative controls) and 13 with 21 thyroid nodules (positive controls). The 12 DTCpatients (19 LNs) with a malignant FNA cytology and/or high FNATg level received LN surgery (11 patients) or I(131)-iodine treatment (1 patient) and the outcome measure was pathological or scintigraphic evidence of DTC LN metastasis. RESULTS: All 26 negative controls showed FNATg <1 ng/FNA and all 21 positive controls showed high levels of FNATg (127-210,000 ng/FNA, median 38,000). Among DTCpatients in 25 LNs with a benign FNA cytology, FNATg was undetectable in 24 and low in 1 (6 ng/FNA); in 19 LNs with a malignant FNA cytology, FNATg was high in 17 (80-140,000 ng/FNA, median 7174 ng/FNA) and low in 2 (6.6 and 7.1 ng/FNA), which proved to be low Tg immunostaining oncocytic DTC metastasis; in 9 LNs with a non-informative cytology, FNATg was undetectable in 8 but 11,825 ng/FNA in 1, which proved a DTC metastasis. Measurement of FNA albumin demonstrated that contamination of FNA by serum proteins was negligible. CONCLUSION: Low FNATg levels can indicate a DTC metastasis. It cannot be related to clinically relevant levels of serum Tg.
Authors: Ivan Blažeković; Matija Romić; Marija Bosak Butković; Ines Šiško Markoš; Vedrana Gladić Nenadić; Valentina Vidranski; Petra Petranović Ovčariček; Dražena Krilić; Tea Varjačić; Josip Staničić; Roko Granić; Marija Punda; Ivan Mihaljević; Tomislav Jukić; Maja Franceschi Journal: Acta Clin Croat Date: 2020-06 Impact factor: 0.780