Unusual presentation and management of parathyroid carcinoma with pulmonary metastasis: a case report.

Background: Parathyroid carcinoma is a rare and challenging malignancy, often confirmed by histopathological analysis. Due to its rarity, it can present in atypically. We present a case of parathyroid carcinoma with an unusual course of pulmonary metastasis emphasizing the complexities of its diagnosis and management.

Case description: A 38-year-old lady was referred to our department when her newborn was found to have hypoparathyroidism. Laboratory tests showed elevated parathyroid hormone (PTH) and adjusted calcium levels. Imaging studies suggested the presence of parathyroid tumors, and histopathology confirmed parathyroid carcinoma. Immunohistochemistry was positive for GATA3 in the tumor cells, and next generation sequencing revealed CDC73 mutation, MYC rearrangement, ASXL1 mutation, and a tumor mutational burden (TMB) of 11 Muts/Mb. Despite surgical intervention and initial remission, she developed pulmonary metastasis, which was surgically addressed. She is currently under immunotherapy with six cycles of pembrolizumab due to recurrence.

Conclusions: This case highlights the importance of prolonged surveillance and imaging for parathyroid carcinoma due to recurrence and metastasis. Aggressive resection of parathyroid carcinoma and metastasis are important to decrease mortality. This case also highlights the importance of genetic factors, like CDC73 mutations, confirmed in this study.