Goiter: Test and Diagnosis

Laboratory parameters of the 1st order – obligatory laboratory tests.

  • Thyroid parameters: TSH (thyroid-stimulating hormone), fT3 (triiodothyronine), fT4 (thyroxine) – for all nodules greater than 1 cm in diameter to assess thyroid functionNote: If TSH is elevated or decreased, free peripheral thyroid hormones fT3 and fT4 should also be determined.

Laboratory parameters 2nd order – depending on the results of the history, physical examination and the obligatory laboratory parameters – for differential diagnostic clarification.

  • Calcitonin – suspected thyroid carcinoma (thyroid cancer); e.g., workup of a scintigraphically cold nodule (usually solid, echo-poor nodule with fuzzy borders on ultrasound), interpretation of calcitonin elevation:
    • Medullary thyroid carcinoma (C-cell carcinoma).
      • Approximately 50% of cases have concurrent pheochromocytoma
      • In 20-30% of cases there is concomitant hyperparathyroidism
  • TPO-Ak (TPO antibodies) – in sonographically echo-poor thyroid and suspected autoimmune thyroid disease such as Hashimoto’s thyroiditis.
  • Fine needle biopsy (FNB) or fine needle aspiration cytology (FNAZ) – for suspicious (suspect) or cold nodules.
    • Germany: puncture for nodes > 1 cm
    • International: puncture also for a 5 mm nodule if sonographically suspicious.
  • Iodine level in the urine – if iodine deficiency or iodine contamination and thereby triggered hyperthyroidism (hyperthyroidism) is suspected.

Further notes

  • According to current recommendations, in the case of a euthyroid cold nodule (after exclusion of thyroid autonomy), there is an indication for FNB (see above ) only if there is a suspicion of malignancy (suspected malignancy) according to ultrasound criteria.
  • Punch biopsy (procedure for obtaining a cylinder of tissue from body regions suspected of disease for the purpose of histological (fine tissue) examination) – for fine needle biopsy of a thyroid nodule with an atypia or follicular lesion of unclear significance (AUS/FLUS).Punch biopsy resulted in a higher incidence of follicular neoplasia or suspected (6.2% vs. 0.7%; nodules > 1 cm: 9.2% vs. 0.7%) and a higher rate of malignancy diagnoses (21.9% vs. 8.5%).Diagnostic accuracy: 92% vs. 87%; sensitivity: 82% vs. 66%; specificity: 100% vs. 99%; positive predictive value: 100% vs. 96%; negative predictive value: 86% vs. 84%.
  • About 10% of all “cold nodules” are malignant. Approximately 80% of these are detected cytologically. Caveat. A negative cytology finding does not exclude a malignancy (malignant tumor) (see above).
  • If thyroid autonomy is detected, clarification of a dignity of the nodule (clarification of whether the nodule is benign or malignant) can be omitted, since as a rule autonomous adenomas are benign (benign).
  • A study that followed nearly 1,000 patients with more than 1,500 thyroid nodules diagnosed as benign over the course of 5 years concluded the following:
    • Thyroid carcinoma was identified in five nodules (0, 3%). Four of these were from the group that had already been punctured at baseline based on suspicious (“suspect”) sonographic criteria, i.e., only 1.1% of the biopsied nodules were classified as false negatives!
    • Only one of 852 nodes <1 cm (0.1%) showed malignancy (malignancy) during follow-up. The nodule did not become conspicuous until the 5th year and showed hypoechogenicity (weakly reflective, echo-poor structures) and fuzzy borders on ultrasound.
    • Nodal growth was usually apparent quite early, often in the first year.

    Conclusion: in the case of small (< 1 cm) and cytologically inconspicuous nodes, a follow-up examination after one year is sufficient. If there is no growth, another examination in 5 years is sufficient. Exceptions are young patients or older obese patients with multiple or large nodes (size < 7.5 mm).