Mediastinal parathyroid carcinoma: a case report and review of the literature

Abstract

Background: Parathyroid carcinoma (PC) is an uncommon cause of primary hyperparathyroidism (PHPT) and particularly rare in the mediastinum. Herein, we present a case of mediastinal PC and conduct a related literature review.

Case presentation: We described a case of a 50-year-old female patient with PHPT due to mediastinal PC. She was initially admitted to a local hospital in her hometown with hypercalcemia and high blood concentrations of PTH (parathyroid hormone). The patient underwent neck parathyroidectomy and pathological examination suggested parathyroid adenoma. Although the overproduction of serum calcium and PTH declined after the surgery, calcium and PTH increased again one month later, so the patient was transferred to our hospital. A 99^mTc-sestamibi scan revealed an ectopic finding in the mediastinum, which was also indicated on the CT image. After removing the mediastinal mass, the metabolism of calcium and PTH quickly reverted to normal and the pathologic features of the mass were consistent with PC. By reviewing the related literature, we noticed that only scattered reports were published before 1982, and those were not included in the present review due to their differences with current radiological examination and treatment methods. After excluding outdated studies, we summarized and analyzed 20 reports of isolated mediastinal PC and concluded that. Parathyroidectomy remains the only curative treatment for the disease. Furthermore, the success of treatment directly depends on accurate preoperative localization.

Conclusion: With this study, we emphasize the importance of accurate preoperative diagnosis of mediastinal PC and improve clinicians' understanding of the disease.

Keywords: Case report; Ectopic; Mediastinum; Parathyroid carcinoma; Primary hyperparathyroidism.

Fig. 1

CT imaging and scintigraphic analysis using technetium-99 m. a A mass is found in the mediastinum on CT imaging. b, c Parathyroid scintigraphy shows high focal radiotracer uptake at 15 and 90 min  after injection of 99mTc-sestamibi

Fig. 2

CT image of the abdomen. The CT scan image shows an enlarged pancreas with indistinct boundaries and surrounding exudates

Fig. 3

Histopathological and immunohistochemical findings. a Histological evaluation shows vascular invasion by parathyroid tumor cells (H&E, ×40). b Immunohistochemical findings show that approximately 10% of the tumor cells were Ki-67 positive (×100)