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

Abstract

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.

Przydatność oznaczania stężenia PTH w popłuczynach z igły do biopsji aspiracyjnej cienkoigłowej w identyfikowaniu patologicznych przytarczyc — analiza czynników wpływających na skuteczność tej metody

“…In the presented study, the routine FNAB allowed us to diagnose parathyroid tissue in 30% of cases. That value is similar to data reported by Bancos et al [20] -31% -and is higher than that showed by Giusti et al [8] -17%. The relatively high percentage of non-diagnostic Comparison of the thyroid size, the size of focal lesion suggestive of pathological parathyroid, and …”

“…However, in all the cases, we observed PTH-FNAB concentrations to be either higher than serum PTH concentrations (frequently elevated into the hundreds or thousands of pg/mL) or very low if not undetectable, doubtlessly negative. Similarly, other reports have indicated that PTH level in the aspirate is rarely equivocal [6,[8][9]24]. Blood contamination in biopsies of non-parathyroid lesions may explain the small amounts of PTH detected in negative aspirates [15].…”

“…The negative influence of the presence of thyroid nodules on both methods has already been described [6,[8][9]24]. An unfavourable effect of coexisting chronic thyroiditis on scintigraphy has been recently reported by Boi et al [9].…”

“…Scintigraphy shows some advantages over US, as it not only localises the lesion, but also allows confirmation of its parathyroid origin. However, thyroid nodularity and the presence of chronic thyroiditis lower the efficiency of both those examinations [3][4][5][6][7][8][9]. Other imaging examinations (e.g.…”

“…The published reports on this method are encouraging so far [6,8,9,[15][16][17][18][19][20][21][22][23][24][25]. But only in a few studies has the influence of co-existing nodular goitre on the discussed method been analysed [6,8,24]. This method has been applied in patients with chronic thyroiditis in a single report only [9].…”