Coincidence or Causality: Parathyroid Carcinoma in Chronic Kidney Disease-Case Report and Literature Review.

Parathyroid carcinoma (PC) associated with primary hyperparathyroidism (PHPT) has been well investigated in recent years. Data regarding PC evolution in secondary hyperparathyroidism (SHPT) due to chronic kidney disease (CKD) are, however, scarce. Most features that raise the suspicion of PC in PHPT are part of the usual SHPT evolution in CKD, mirroring the natural changes undergone by the parathyroid glands. Therefore, pre-surgically establishing the malignant or benign character of the lesions is cumbersome. We present two cases of PC in end-stage renal disease, one of which was bilateral, diagnosed after total parathyroidectomy in a high-volume parathyroid surgery center. A literature review of the data was also performed. A systematic search of the PubMed/MEDLINE database until January 2024 identified 42 cases of PC associated with SHPT. Understanding the PC features in CKD might improve associated bone and mineral disease management, and reduce the risk of metastasis, parathyromatosis, or recurrence. Irradiation, prolonged immunosuppression, long dialysis vintage, and genotype may predispose to the malignant transformation of chronically stimulated parathyroids. Despite postsurgical diagnosis, favorable outcomes occurred when distant metastases were absent, even without "en bloc" resection. Further research is warranted to delineate specific diagnostic and therapeutic approaches tailored to this particular patient subpopulation.

FGF23 and primary hyperparathyroidism: is there a link?

INTRODUCTION: Data regarding the role of fibroblast growth factor 23 (FGF23) in primary hyperparathyroidism (PHPT) are scarce and discordant. Our study aimed to evaluate the prognostic impact of FGF23 upon the clinical and biochemical evolution of PHPT. MATERIAL AND METHODS: Forty-two patients with ages between 30 and 80 years, diagnosed with PHPT caused by a sporadic, solitary parathyroid adenoma, and referred to surgery (minimally invasive parathyroidectomy) were prospectively included in the study. Serum levels of FGF23, PTH, 25(OH)D3, calcium (Ca), phosphate (P), total procollagen type 1 N-terminal propeptide, and C-terminal telopeptide of type I collagen were determined at baseline (preoperatory), one day after surgery, and in 13 patients also prospectively at three, six, and 12 months. Bone mineral density (BMD) was also evaluated before surgery in all patients and 12 months after surgery in the 13 followed up patients. RESULTS: In the 42 PHPT patients with D hypovitaminosis (mean 25(OH)D3 levels of 16.2 ± 1.5 ng/mL), preoperatory serum FGF23 concentration was within the normal range (75.55 ± 3.39 pg/mL) and remained unchanged one day post operation (81.69 ± 4.67 pg/mL, p = non-significant). The 13 patients followed prospectively for up to 12 months after surgery also showed unmodified FGF23 levels (80.9 ± 11.03 pg/mL, p = non-significant), despite PTH and Ca normalisation and vitamin D replenishment. Preoperatory FGF23 negatively correlated with PTH (r = -0.37, p = 0.038), but not with 25(OH)D3, Ca, P, bone mass, or metabolism markers. CONCLUSIONS: In PHPT, correlations between FGF23 and PTH seem rather an epiphenomenon. Therefore, we think that FGF23 evaluation and dynamics are not informative regarding PHPT severity. (Endokrynol Pol 2020; 71 (4): 306-312).

Coexistent papillary thyroid carcinoma diagnosed in surgically treated patients for primary versus secondary hyperparathyroidism: same incidence, different characteristics.

BACKGROUND: The coexistence of hyperparathyroidism and thyroid cancer presents important diagnostic and management challenges. With minimally invasive parathyroid surgery trending, preoperative thyroid imaging becomes more important as concomitant thyroid and parathyroid lesions are reported. The aim of the study was to evaluate the rate of thyroid cancer in patients operated for either primary (PHPT) or secondary hyperparathyroidism (SHPT). METHODS: Our retrospective study included PHPT and SHPT patients submitted to parathyroidectomy and, when indicated, concomitant thyroid surgery between 2010 and 2017. RESULTS: Parathyroidectomy was performed in 217 patients: 140 (64.5%) for PHPT and 77 (35.5%) for SHPT. Concomitant thyroid surgery was performed in 75 patients with PHPT (53.6%), and 19 papillary thyroid carcinomas (PTC) were found, accounting for 13.6% from all cases with PHPT and 25.3% from PHPT cases with concomitant thyroid surgery. Thirty-one of operated SHPT patients (40.3%) also underwent thyroid surgery and 9 PTC cases were diagnosed (11.7% of all SHPT patients and 29% of patients with concomitant thyroid surgery). We found differences between PHPT and SHPT patients (p < 0.001) with respect to age (54.6 ± 13y versus 48.8 ± 12y), female-to-male ratio (8:1 versus ~ 1:1), surgical technique (single gland parathyroidectomy in 82.8% PHPT cases; versus subtotal parathyroidectomy in 85.7% SHPT cases) and presurgical PTH (357.51 ± 38.11 pg/ml versus 1020 ± 161.38 pg/ml). Morphopathological particularities, TNM classification and multifocality incidence of PTC were similar in the two groups. All PTC from patients with SHPT were thyroid microcarcinomas (TMC, i.e. tumors with a diameter smaller than 1 cm), whereas seven out of the 19 cases with PTC and PHPT were larger than 1 cm. CONCLUSIONS: PTC was frequently and similarly associated with both PHPT and SHPT irrespective of presurgical PTH levels. Thyroid tumors above 1 cm were found only in patients with PHPT. Investigators should focus also on associated thyroid nodular pathology in patients with PHPT.