# Coincidence or Causality: Parathyroid Carcinoma in Chronic Kidney Disease—Case Report and Literature Review

## TL;DR

This paper reports two cases of parathyroid carcinoma in patients with chronic kidney disease and reviews existing literature to better understand its diagnosis and treatment challenges.

## Contribution

The paper presents two new clinical cases and a literature review on parathyroid carcinoma in the context of chronic kidney disease.

## Key findings

- Parathyroid carcinoma in CKD is difficult to distinguish from benign lesions pre-surgery due to overlapping features.
- Forty-two cases of PC associated with secondary hyperparathyroidism were identified in the literature review.
- Favorable outcomes were observed when distant metastases were absent, even without en bloc resection.

## Abstract

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.