Current Understanding and Management of Parathyroid Carcinoma

Abstract

Parathyroid adenomas are a very common endocrine entity, whereas parathyroid carcinomas (PC) are extremely rare. With an estimated incidence of 0.015 per 100,000 population and an estimated prevalence of 0.005% in the United States, parathyroid cancer is one of the rarest of all human malignancies. PC is an extremely rare cause of primary hyperparathyroidism (PHPT). Men and women are equally affected, usually in the fourth or fifth decade of life. The exact etiology has not been identified, but mutations in the CDC73 gene appear to have a critical role in its pathogenesis. The morbidity and mortality of PC is secondary to the hypercalcemia resulting from tumor overproduction of PTH. The primary management objectives are complete removal of the cancer and prevention of recurrences. This review will talk about the epidemiology, etiology, clinical manifestations, and management of PC.

<sup>11</sup>C-Choline PET/CT in the Management of Primary Hyperparathyroidism

“…Primary hyperparathyroidism (PHPT) is defined as hypercalcemia or widely fluctuating serum calcium levels caused by the inappropriate secretion of parathyroid hormone (PTH) by one or more parathyroid glands [1] PHPT is symptomatic in more than 95% of the cases, but symptoms may be subtle [15]. The "classic" pentad of kidney stones, painful bones, abdominal groans, psychic moans, and fatigue overtones is rarely seen today [16] [17] [18].…”

“…Thus, PET/CT with 18 F-Fluorocholine has the ability to detect not only parathyroid adenomas measuring less than 1cm, but also carcinomas, multiple adenomas, and even gland hyperplasia in patients with secondary hyperparathyroidism. The tracer 18 F-Fluorocholine (5 to 10 mCi) is usually injected intravenously and the scan is acquired after 5 -15 minutes.…”

“…The tracer 18 F-Fluorocholine (5 to 10 mCi) is usually injected intravenously and the scan is acquired after 5 -15 minutes. 18 F-Fluorocholine is a positron emitter with half-life of 109.7 minutes and Emax of 1.656 MeV; it is cleared via the kidneys and excreted in the urine [53] [54].…”

“…When compared to 99m Tc-Sesta-MIBI imaging, PET/CT with 18 F-Fluorocholine has shown improved spatial resolution allowing for detection of smaller lesions.…”

“…In contrast to what occurs with 99m Tc-Sesta-MIBI, PET/CT with 18 F-Fluorocholine has proven to be able to detect hyperfunctioning parathyroid adenomas in normocalcemic PHTP as in overt PHPT [55]. In addition, because of the rapid biokinetics of choline, it is associated with a shorter study protocol.…”