Commentary: Case Report: Abdominal Lymph Node Metastases of Parathyroid Carcinoma: Diagnostic Workup, Molecular Diagnosis, and Clinical Management.

Notably, immunohistochemistry-assessed PD-L1 expression was found in 4/18 patients (22.2%) with histologically confirmed PC ([10]), thus suggesting that immune checkpoint blockade may have a rationale in the treatment of this type of tumours. As a further reason of interest, hypocalcemia due to immune-related hypoparathyroidism has been reported as a rare complication following anti-PD-1 therapy initiation in patients with non-parathyroid tumours ([23], [24]). Keywords: parathyroid carcinoma; immune checkpoint inhibitors; ipilimumab; nivolumab; pembrolizumab EN parathyroid carcinoma immune checkpoint inhibitors ipilimumab nivolumab pembrolizumab 1 3 3 06/23/21 20210618 NES 210618 Introduction In the issue of March 2021, Lenschow et al. reported the case of a 46-year-old woman with recurrent, programmed death-ligand-1 (PD-L1) negative, tumor mutational burden (TMB)-high parathyroid carcinoma (PC), who showed stable disease as her best response on imaging, and a three-fold drop in PTH after treatment with intravenous pembrolizumab ([1]). [Extracted from the article]