[Usefulness of the determination of thyroglobulin in lymph node aspirates of patients with papillary thyroid carcinoma and positive antithyroglobulin antibodies].

Objective: We wanted to study the utility of thyroglobulin determination in the washout of fine needle aspiration (FNAB-Tg) of lymph metastatic nodes in patients with papillar thyroid carcinoma (PTC) and positive serum thyroglobulin antibodies (AbTg).

Materials And Methods: We have studied 11 patients (49.9+/-11.8 years old, 70% females) with PTC and positive AbTg in which a whole-body scanning (WBS) after (131)I treatment showed pathological uptake in lymph cervical nodes. An ultrasound-guided fine-needle aspiration biopsy (US-FNAB) was performed for cytological research. Needle-washout with 1 ml ClNa 0.9% was employed to determine FNAB-Tg.

Results: In 16/17 suspicious nodes Tg-FNAB concentration was higher than 7 ng/dl (223.3+/-314.2 [7-1009]). AbTg were negative in the washout obtained. WBS was able to detect 94% lymphadenopathies, whereas 76.5% were detected with ultrasound and 70.6% using cytology. The FNAB-Tg was positive in 94% of nodules, which was higher than combining US and FNAB-cytology both together (88.2%). One hundred per cent of pathological nodules were detected using US plus FNAB-Tg.

Conclusions: FNAB-Tg determination is an useful technique for diagnosis of metastatic lymph nodes of patients with PTC and is unaffected by the presence of serum AbTg.