Prevalence of Thyroid Nodules and Carcinomas in Patients Operated on for Renal Hyperparathyroidism: Experience with 339 Consecutive Patients and Review of the Literature

Abstract

The association between renal hyperparathyroidism (HPT) and differentiated thyroid carcinoma is discussed. To determine the prevalence and potential risk factors, we performed a retrospective analysis of our patients (1998-2004) and compared the data with the data from other surgical and autopsy studies. At our hospital, a total of 347 parathyroidectomies in 339 patients with renal HPT were performed. Most patients underwent preoperative ultrasound investigation of the thyroid gland and, if indicate, thyroid scintigraphy. Intraoperatively, both thyroid lobes were mobilized and palpated. Detected thyroid nodules were adequately resected and investigated histologically. A systematic analysis of the international literature was performed using the PubMed/MEDLINE system to identify publications on the prevalence of papillary thyroid carcinoma (PTC) in patients with renal HPT and in the overall population. Altogether, 133 patients (39.2%) underwent simultaneous thyroid surgery. The initial operation was hemithyroidectomy in 55 (16.2%), Dunhill operation in 36 (10.6%), unilateral subtotal resection in 17 (5.0%), bilateral subtotal resection in 5 (1.5%), and enucleation of a thyroid nodule in 18 (5.3%). A PTC was found in 8 of 339 patients (2.4%) and a follicular thyroid carcinoma in 1. Among 311 patients with primary cervical operation, 6 (1.9%) had a papillary thyroid carcinoma. All papillary tumors were classified as pT1 with a diameter of 1 to 12 mm; three were bifocal, and only one patient had positive lymph nodes. None of the analyzed factors showed a significant correlation with the occurrence of thyroid carcinoma. Depending on the screening method, the prevalence of occult PTC in European autopsy studies ranged from 5% to 9% and was markedly higher in almost all studies than in the present one. The prevalence of PTC in the present study makes an etiologic association between renal HPT and PTC unlikely. The clinical significance of these tumors remains unclear because all incidental tumors were small. However, if easily and safely feasible, relevant thyroid nodules should be removed during parathyroid surgery.

Clinicopathological Characteristics of Thyroid Cancer in Patients on Dialysis for End-Stage Renal Disease

“…Some authors have suggested that there is an association between secondary HPT and PTC (8,23). But in a large cohort study of 339 operated renal HPT cases from Germany, the prevalence of PTC (2.4%) has made an etiologic association between renal HPT and PTC unlikely (13). In our study, there was also no association between biochemically and=or histopathologically proven renal HPT and PTC.…”

“…In the same study, the frequency of thyroid tumors rose with the duration of dialysis. In another study, age and duration of dialysis were not found to be correlated with thyroid cancer development (13). In most autopsy studies in a normal population, a correlation with increasing age was found (14)(15)(16).…”

Incidental Finding of Papillary Thyroid Carcinoma in the Patients with Primary Hyperparathyroidism

“…In our study, favourable results on these parameters were observed. Most of the coincidental thyroid cancers were reported as PTC and in small size, particularly micro-papillary carcinoma [5,12,16,17]. Likewise, in our series, no need for further intervention was required due to majority of papillary microcarcinoma and small sized PTC without capsular infiltration.…”

“…However, an increased risk of non-parathyroid cancers in patients with pHPT has been reported in several studies [18]. Miccoli et al [13] reported thyroid malignancy as the most prevalent cancer among those patients in whom pHPT was [4,5,17,[19][20][21], others investigated several predisposing factors such as exposure to neck radiation, goitregenic effect and increased mitotic activity induced by hypercalcemia [22,23]. In addition, tumour-promoting effect of parathyroid hormone and subsequent genetic predisposition to new malignancies were also noted [16,24].…”

Preoperative localization and minimally invasive management of primary hyperparathyroidism concomitant with thyroid disease

“…It is of interest that the frequency of concomitant thyroid malignancy is lower than that in other studies. This could be explained partly by the fact that the relatively rarer use of neck irradiation therapy in China than in western country (Seehofer et al, 2005).…”