Non-Functional Parathyroid Carcinoma: A Review of the Literature and Report of a Case Requiring Extensive Surgery

Abstract

Parathyroid carcinoma is a rare malignancy, and only accounts for 0.5–2% of cases of primary hyperparathyroidism. Less than 10% of parathyroid carcinomas are non-functional, and as such, they have been rarely reported in the literature. Importantly, margin status at resection is related to prognosis, and only a handful of case reports of non-functional carcinoma note this important parameter. Here we report the first case of non-functional parathyroid carcinoma with negative margins, and review the literature on this rare entity. Whether functional or non-functional, parathyroid carcinoma can often be difficult to differentiate from benign parathyroid adenoma. While diagnosis has been based on clinical and histological criteria, recent data concerning the molecular underpinnings of parathyroid carcinoma may allow for improved accuracy in distinguishing benign and malignant parathyroid tumors.

Rak przytarczycy jako przedoperacyjny dylemat diagnostyczny – opis przypadku i przegląd piśmiennictwa

“…Parathyroid carcinoma presented as a hypofunctional lesion only in the early phase of the study on scintigraphy. This is not concordant with the literature [19,20,21]. Recently, another case report with a negative 99mTc-MIBI scan but positive 18F-FDG-PET scan was presented.…”

Non-functional parathyroid carcinoma: a case report and review of the literature

“…To date, 32 cases (Table-1) have been reported in the literature. 2, An additional 6 cases were mentioned in the literature but were not accessible for this review. 3,[34][35][36][37][38] Patients with non-functional parathyroid carcinoma, as the name implies, have normal serum PTH levels but do not present with symptoms of hypercalcemia.…”

“…40 As shown in Table-1, more than half of cases come to the hospital because of a neck mass The non-secretory state, including the decreased or impaired synthesis of hormone, the production and secretion of an abnormalinactive hormone, or the impaired secretion of hormone, is one cause of non-functional PTC. 2 Based on the hypothesis of impaired hormone secretion, studies on the ultrastructure of nonfunctioning PTCs have found that the number of cytoplasmic organellesis increased, especially in the Golgi apparatus. Moreover, the amounts of cytoplasmic secretory granules, occasionallipid vacuoles, and glycogen are increased.…”

“…Solid nests of tumor cells have been observed with tumor cells accounting for approximately onequarter of the tissue examined, which is separated by a dense fibrotic stroma. 2 In 1973, Schantz and Castleman, 52 reported the histological criteria for the diagnosis of parathyroid carcinoma, and these criteria remain valid today, which include sheets or lobules of tumor cells separated by dense fibrous bands, mitotic figures, necrosis, capsular invasion, or vascular invasion. However, the specificity of these criteria is not particularly high because these characteristics can be observed in certain benign tumors.…”

“…1 Less than 10% of cases of parathyroid carcinoma are non-functional, 2 presenting with normal levels of parathyroid hormone. De Quervain, 3 described the first known case in 1909, and to date, few cases have been reported in the literature.…”