Hyperfunctioning parathyroid tumours in patients with thyroid nodules. Sensitivity and positive predictive value of high-resolution ultrasonography and 99mTc-sestamibi scintigraphy.

Abstract

A series of 112 consecutive patients with primary hyperparathyroidism who underwent both high-resolution neck ultrasonography (US) and Tc-pertechnetate subtraction scintigraphy (SS) prior to successful parathyroidectomy was reviewed. There were 29 (25.9%) men and 83 (74.1%) women, with a median age of 58 years (range 13-78 years). Patients were divided into two groups, according to the preoperative US findings: group A (87 patients, 77.7%) without thyroid diseases, and group B (25 patients, 22.3%) with either multinodular goitre or a solitary nontoxic thyroid nodule. In group B patients partial or total thyroidectomy was also performed, according to the intraoperative findings and frozen-section examination results. Final histopathology showed 99 (88.4%) solitary parathyroid (PT) adenomas and 3 (2.7%) PT carcinomas, while 10 (8.9%) patients had a multiglandular disease. The sensitivity and positive predictive value (PPV) were (group A vs group B) 79.8% vs 70.8% (P = 0.25) and 95.7% vs 94.4% (P = 0.58) for US, and 83.3% vs 87.0% (P = 0.47) and 95.9% vs 90.9% (P = 0.32) for SS respectively. Better but similar (P = not significant) results were obtained in patients with solitary PT tumours: 81.5% vs 77.8% (US) and 85.0 vs 94.1% (SS) sensitivity; 97.1% vs 93.3% (US) and 95.8% vs 88.9% (SS) PPV. Overall, the combination of US and SS was 92.9% sensitive (group A = 93.1%, group B = 92.0%; P = 0.55), and the PPV reached 100% in each group. In conclusion, in patients with primary hyperparathyroidism the results of both US and SS are independent of coexistent thyroid disease, especially in patients with solitary PT tumours.

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

“…Normal parathyroid glands are not visible on US and false positive results are due to thyroid nodules, blood vessels, oesophagus, long collum muscle, and lateral cervical lymph nodes, while false negative results are due to atypical parathyroid location (Solbiati et al, 2001). Thyroid nodules were reported during neck US in 20%~80% of PHP cases (Abraham et al, 2007;Erbil et al, 2007;Lumachi et al, 2003;Marcocci et al, 1998;Mihai et al, 2006). Moreover, sensitivity and PPV were heavily influenced by concomitant unior multi-nodular thyroid goitre (Erbil et al, 2007;Mihai et al, 2006).…”

Thyroid diseases cause mismatch between MIBI scan and neck ultrasound in the diagnosis of hyperfunctioning parathyroids: usefulness of FNA–PTH assay

“…False-negative neck US results may be rarely found in cases with small and ectopic HP, intrathyroidal HP, and underscent HP situated along the common carotid artery or recurrent laryngeal nerve, while false-negative MIBI scans have been observed in the presence of small size, low oxyphil cell content, and morphological changes (cystic degeneration, apoptosis, or necrosis) of HP (18,19). On the other hand, difficulty in neck US and MIBI scan interpretation has been described in the presence of TNs (20,26,36) with high rate of false-positive images (15-20%) for both techniques (24,37); blood vessels, esophagus, longus colli muscle, and enlarged lymph nodes (37) may represent other rare sources of falsepositive results. In contrast with nodular thyroid diseases, no studies on the potential interference of concomitant AITD in the diagnostic approach of pHPT by MIBI scan and neck US have been so far performed.…”

“…On the other hand, MIBI retention is not parathyroid specific and is also observed in hypermetabolic thyroid nodules (TNs) such as oncocytic tumors (20) and autonomous thyroid adenomas (TA) (20,21). Neck US is the least invasive and cheapest method (11,22) to accurately localize HP, but its efficacy is related to the operator experience and may be reduced in the presence of concomitant nodular goiter (NG) (23,24). No studies on the potential interference of autoimmune thyroid disease (AITD), such as Hashimoto's thyroiditis (HT) and Graves' disease (GD) in HP localization by MIBI scan and neck US, have been so far performed.…”

“…No studies on the potential interference of autoimmune thyroid disease (AITD), such as Hashimoto's thyroiditis (HT) and Graves' disease (GD) in HP localization by MIBI scan and neck US, have been so far performed. Finally, other potential conditions leading to uncertain HP localization by these techniques are represented by ectopic parathyroid location, multiglandular HP hyperplasia, and exceptionally lymphoadenopathies (20,24,25).…”

BEST PRACTICE NO 183: Examination of parathyroid gland specimens

“…28 Sestamibi scanning has a high positive predictive value, but is more accurate for single gland rather than multigland disease. [29][30][31][32] High resolution ultrasound scanning alone is less accurate than sestamibi scanning, but used in combination the accuracy of detection improves, [33][34][35] especially for single gland disease. 29 There is a false negative rate of up to 22% with sestamibi scans in primary hyperparathyroidism; this is more likely with small adenomas, multigland disease, superior glands, or normal preoperative calcium concentrations.…”