The diagnostic value of parathyroid hormone washout in primary hyperparathyroidism patients with negative or equivocal 99 m Tc‐MIBI results

Abstract

Background and objectives The accurate identification of hyper functioning parathyroid gland is needed for definitive surgical treatment in primary hyperparathyroidism. Ultrasonography and 99mTechnetium sestamibi scintigraphy are the two most used methods with varying sensitivities. This study aimed to assess the value of parathyroid hormone (PTH) assay in preoperative ultrasound guided fine needle aspiration (FNA)‐PTH washout fluid to verify the correct localisation of lesions with negative or inconclusive scintigraphy results. Methods We evaluated data of 28 lesions in 21 patients who underwent US‐guided parathyroid fine‐needle aspiration (FNA) with PTH washout, retrospectively. The PTH washout results and the reports of parathyroid surgery and imaging studies were reviewed. Results Of operated 28 lesions 23 had positive and 5 had negative washout results. The median FNA‐PTH washout was 2315.5 pg/ ml (min–max: 12.3‐6978 pg/ ml). The calculated sensitivity of FNA‐PTH washout was 85.7% and the specifity was 28.6%. The positive and negative predictive values were 78.3% and 40.0%, respectively. Conclusions FNA‐PTH can be used to establish the nature of the lesion, discriminate parathyroid gland from thyroid lesions or cervical lymph nodes, improving the surgical outcomes. It can be used to localise parathyroid lesions preoperatively when negative or discordant ultrasound and scintigraphy findings are obtained.

Two cases of spontaneous remission of primary hyperparathyroidism due to auto-infarction: different management and their outcomes

“…Both cases were discussed on the local endocrine multidisciplinary team (MDT) meetings and it was felt that the benefits of establishing the correct diagnosis outweighed the risks linked with the procedure itself including discomfort, pain or bleeding, but mainly the risk of tumour dissemination in cases of confirmed malignancy. The use of FNA under such and similar circumstances is based on our previous experience and has been reported by our group (15) as well as others (16, 17).…”

Primary hyperparathyroidism with surgical indication and negative or equivocal scintigraphy: safety and reliability of PTH washout. A systematic review and meta-analysis

“…We found only two studies reporting an adequate number of lesions other than parathyroid: in Aydin et al 2019 there were five false positive out of seven evaluated masses, while in Boi et al 2013 all the 19 lesions were correctly classified as true negative with US-guided FNA. No reason for the low specificity in the former paper was reported (21,23).…”

“…Despite the differences above, high sensitivity with no heterogeneity and moderate specificity were found, with out-of-scale results in histology-proven parathyroid lesions frequently reported (20,23,26). The limited number of false-negative results could be due to insufficient aspiration, aspiration of adjacent tissues instead of parathyroid lesion in the cases of very small lesions or unusual locations, PTH truncated fragments; false positive could be attributed to blood contamination or hook effect (21,26,37). Finally, a possible reason for misclassification is represented by the circadian and seasonal rhythms of serum PTH, as well as the influence of physical exercise.…”

“…The characteristics of the included articles are summarized in Table 1 (19,20,21,22,23,24,25,26,27). The papers were published between 1998 and 2018, had sample sizes ranging from 6 to 44 patients.…”

“…FNA-PTH was performed with a 21-to 27-gauge needle, washed out with 0.5-1 mL of 0.9% saline or PTH-free serum. The result was considered as positive if higher than patient's serum PTH level at the time of sampling in four studies (19,21,24,25), two times this level in one (22); the remaining papers reported a cutoff ranging from 40 to 103 pg/mL (Table 2) (20,23,26,27). Overall, 222 lesions in 182 patients were evaluated.…”