Primary Hyperparathyroidism: Can Parathyroid Carcinoma Be Anticipated on Clinical and Biochemical Grounds? Report of Nine Cases and Review of the Literature

Abstract

Serum calcium, PTH levels, and tumor weights were significantly greater in the PC subgroup, even if not invariably in a discriminatory way. However, when PTH is <4 times the upper limit of normal and tumor weight is <1.9 g, the probability of PC is nil.

Ultrasound features of malignancy in the preoperative diagnosis of parathyroid cancer: a retrospective analysis of parathyroid tumours larger than 15 mm

“…Parathyroid cancer has a broad spectrum of clinical presentation but tends to be seen with higher calcium and parathyroid hormone (PTH) levels, often significant bone disease and not infrequently a palpable mass [4,5]. A recent review revealed that malignancy is extraordinarily rare in lesions <15 mm, with only 6 reported cases in the world literature [4], whilst most reports on large cohorts identify parathyroid malignancy in 0.5-3% of all patients with pHPT [5][6][7]. Based on this observation a tool for discriminating between benign and malignant lesions is needed for lesions >15 mm.…”

Parathyroid carcinoma and oxyphil parathyroid adenoma: an uncommon case of misinterpretation in clinical practice

“…After three months the patient complained of dyspnea with a dry cough and persistent hoarseness; videolaryngoscopy confirmed left vocal fold paralysis and a CT scan of the chest identified areas of parenchymal condensation with air bronchogram in the upper lobes of both lungs and in the apical segment of the lower lobe of the left lung, with an appearance suggestive of actinic pneumonitis. Bronchoscopy was performed to rule out pulmonary infections including tuberculosis and fun-frequently detected despite Brazil's latitude [32,33] and eventually aggravated by the increased renal conversion of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D induced by chronic PTH overproduction [34,35]. Although 25-hydroxyvitamin D was not measured, the long period of normocalcemic hyperparathyroidism between the first and the second parathyroidectomies, can indicate vitamin D deficiency.…”

“…However, PTH levels of approximately 2,000 pg/mL evident in this case would justify a diagnosis of osteitis fibrosa. According to the literature, diagnosis of parathyroid carcinoma must be based on the concurrence of the following evidence: concomitant renal and bone disease, palpable neck mass, increased tumor weight (>1.9 g), elevated serum calcium levels (between 14-16 mg / dL) and elevated PTH levels (> 500 pg/mL and often > 1000 pg/ mL) [34][35][36]. Therefore, although data from the patient were not conclusive for a malignancy per se, elevated PTH levels should have led to the hypothesis that parathyroid carcinoma was the cause of the primary hyperparathyroidism.…”

A Parathyroid Adenoma: Benign Disease Presenting with Hyperparathyroid Crisis

“…There has been recent work into Preoperative diagnosis based on biochemical grounds with a raised CCa 2+ and PTH increasing the index of suspicion for malignant disease suggesting that serum PTH levels are mildly elevated in benign disease, but carcinoma causes levels up to 10 times that of normal [1]. To further stress the benefit of PTH in preoperative diagnosis, Robert et al suggested that a PTH level <4 times the upper limit of normal excludes a malignancy [4]. Other studies support the above trend—a recent case series looking at solitary adenomas causing asymptomatic disease have derived mean values of Preoperative PTH as 186 [5] and 165 ng/L [6], while research into carcinoma show higher PTH levels of 714 [2] and 1220 ng/L [7].…”