Is Primary Hyperparathyroidism a Risk Factor for Papillary Thyroid Cancer? An Exemplar Study and Literature Review

Abstract

Introduction Primary hyperparathyroidism (PHPT) is associated with several cancer types, including papillary thyroid carcinoma (PTC). Objective To explore further the relation between PHPT and PTC. Methods By considering patients with PHPT as extra-suspicious for PTC, we studied an exemplar group of patients with PHPT with a small (≤1 cm) thyroid nodule, which was negative in preoperative cytologic examination. During parathyroidectomy, a frozen section biopsy of the thyroid nodule confirmed PTC, as did the final surgical specimen, revealing that the preoperative cytology was false-negative. Additionally, relevant reports retrieved from the English literature addressing thyroid cancer and hyperparathyroidism were reviewed and processed. Results Four patients with PHPT were studied. Three had a multifocal thyroid disease, and three had neck lymph node metastasis. Processing previous report data supported an association between PHPT and PTC. Although thyroid nodularity among patients with PHPT was similar to the general population, PTC incidence was higher. This was true also for patients with secondary hyperparathyroidism. Conclusions This study emphasized that PHPT should be considered as a noteworthy risk factor for PTC. Fine needle aspiration of a thyroid nodule is the most valuable diagnostic procedure for thyroid cancer. Yet, false-negative results were reported in up to 10% of cases, especially in small, subcentimeter nodules. In line with our data and the literature, patients with PHPT should have both a detailed ultrasound addressing the thyroid and cytology of any thyroid nodule, including small subcentimeter lesions. Moreover, surgical flexibility, allowing intraoperative thyroid nodule sampling, should be considered even for “innocent” nodules.

Symptomatic Primary Hyperparathyroidism as a Risk Factor for Differentiated Thyroid Cancer

“…The majority of the reported studies were made in patients with PHPT in different stages of evolution [15, 16]. In the present study, in which we included patients with symptomatic PHPT, we found a prevalence of CPT in 20%.…”

“…PTC occurs in 7 to 15% of cases and is related to risk factors as age, sex, radiation exposition, family history, among others [13]. It calls to attention that, in patients with PHPT, the prevalence of thyroid nodular disease is similar that in general population; nevertheless, CPT is more frequent than in general population [15, 16]. The high concurrence of these two diseases in the same patients may not be a coincidence; a lot of factors may connect PHTP with CPT.…”

Association of Hyperparathyroidism and Papillary Thyroid Cancer: A Multicenter Retrospective Study

“…Concomitant pHPT and thyroid malignancy have been reported in several studies since the first cases were reported by Ogburn and Black [ 7 ] in 1956. In pHPT patients, several studies reported the prevalence of papillary thyroid cancer (PTC) to range from 2% to 15% [ 8 , 9 ]. Data on the association between sHPT and PTC is more limited.…”

Increased thyroid malignancy in patients with primary hyperparathyroidism

“…Previous studies have reported 15–75% of patients with PHPT have concomitant thyroid nodules ( 8 , 9 ). Moreover, several authors have described a rate of thyroid cancer in patients with PHPT that appears to be higher than the general population ( 4 , 10 , 11 , 12 , 13 , 14 , 15 ). A review of data from nine studies, including a total of 2510 patients with PHPT requiring parathyroidectomy, indicated an incidence for thyroid cancer of 5%, compared to international estimates ranging from ~2 to 12 per 100,000 thyroid cancer new cases per year ( 15 ).…”