Institutional experience of PTH evaluation on fine-needle washing after aspiration biopsy to locate hyperfunctioning parathyroid tissue.

Assaying parathyroid hormone (PTH) in the washing liquid after fine-needle aspiration biopsy (FNAB) seems to be a valid approach to locate parathyroid tissue. PTH-FNAB was evaluated in 47 patients with a clinical picture of primary hyperparathyroidism (PHP) and ultrasonography (US) suggestive of parathyroid lesion. The patients were subdivided into two groups on the basis of the absence or presence of US thyroid alterations. The result of PTH-FNAB was compared with those of cytology, scintigraphy and, in 24 patients, surgical outcome. PTH-FNAB samples with a value higher than that recorded in the serum and higher than our institutional cut-off were deemed to be probable samples of parathyroid tissue. Cytology proved diagnostic for benign thyroid lesions, non-diagnostic for thyroid lesions, hyperplastic parathyroid tissue, undetermined or malignant thyroid lesions and other lesions in 45%, 30%, 17%, 4%, and 4% of cases, respectively. In 47% of cases, PTH-FNAB indicated that the sample had been taken in parathyroid tissue. In patients without US alterations, the diagnostic accuracy of PTH-FNAB was greater than that of scintigraphy. After surgery, comparison between the results of PTH-FNAB and scintigraphy, in terms of positive predictive value (PPV), revealed the superiority of PTH-FNAB; PPV was 94% for FNAB and 71% for scintigraphy, while sensitivity was 83% and 69%, respectively. PTH-FNAB evaluation after FNAB appears to be more diagnostic than cytology and scintigraphy. Of all the procedures used, PTH-FNAB appears to be the method of choice when the target is US suggestive and reachable. PTH-FNAB appears to be a useful method of guiding surgical intervention.

Recombinant human thyroid stimulating hormone does not acutely change serum osteoprotegerin and soluble receptor activator of nuclear factor-kappaBeta ligand in patients under evaluation for differentiated thyroid carcinoma.

OBJECTIVE: Some extra-thyroid actions of thyroid stimulating hormone (TSH), such as an in vitro action on bone, have been described. Our aim was to evaluate in vivo the acute effect of a recombinant human TSH (rhTSH)-induced TSH surge on Osteoprotegerin (OPG) and receptor activator of the nuclear factor-kappaBeta (RANK-L) levels in patients under levo-thyroxine (L-T4) therapy. DESIGN: 24 patients with differentiated thyroid carcinoma (DTC) were studied. Standard rhTSH testing was performed. OPG, RANK-L, TSH, thyroid hormones, thyroglobulin and several parameters of bone metabolism were evaluated. RESULTS: Baseline OPG and RANK-L levels were in the range of our reference population. An inverse correlation between OPG and spinal Z-score (p=0.029) and between RANK-L and age (p=0.018) or urinary calcium/creatinine ratio (p=0.011) was detected. After rhTSH administration, a significant (p<0.001) increase in TSH was found. No significant increase in OPG or RANK-L levels after rhTSH was observed. No correlation was detected between TSH peak value after rhTSH and maximal percentage change in OPG or RANK-L. A slight increase in urinary cross-links after rhTSH was found. CONCLUSIONS: In a small group of subjects with a history of DTC on L-T4 regimen, our study did not support an acute direct effect of TSH on OPG and RANK-L.