Primary Hyperparathyroidism Secondary to a Sestamibi-Negative Cystic Parathyroid Adenoma.

Timur Gusov,George M Win,Michael J Gardner,Fnu Marium

doi:10.7759/cureus.17577

Abstract

The most common cause of primary hyperparathyroidism (PHPT) is a solid parathyroid adenoma. Less than 2% of cases of PHPT are caused by cystic parathyroid adenomas formed from degeneration of pre-existing solid parathyroid adenomas. Cystic parathyroid adenomas are non-functional in over 90% of cases. In this case we describe management of a 56-year-old man with acute-onset polydipsia, polyuria, xerostomia, nausea, and constipation. Serum chemistry upon admission revealed hypercalcemia, hyperparathyroidism, and reduced serum phosphorus. Neck sonogram revealed a predominantly anechoic lesion later confirmed by pathology to be a cystic parathyroid adenoma in the right thyroid lobe. Sestamibi scan did not show uptake in parathyroid gland, and parathyroid hormone (PTH) was elevated in fine-needle aspiration sample. Otolaryngology removed the cystic lesion via surgical excision, which led to normalization of PTH level. This case demonstrates the importance of evaluation of cystic components for PTH levels and if confirmed should be treated as a parathyroid adenoma.

Highlights

Primary hyperparathyroidism (PHPT) refers to excessive secretion of parathyroid hormone (PTH) from the parathyroid glands
The most common cause of PHPT is from a solid parathyroid adenoma [2]
We describe a case of PHPT secondary to a 99mTc sestamibi-negative parathyroid cystic adenoma in a patient with presentation of acute-onset polydipsia, polyuria, xerostomia, nausea, and constipation

Summary

Introduction

Primary hyperparathyroidism (PHPT) refers to excessive secretion of parathyroid hormone (PTH) from the parathyroid glands. We describe a case of PHPT secondary to a 99mTc sestamibi-negative parathyroid cystic adenoma in a patient with presentation of acute-onset polydipsia, polyuria, xerostomia, nausea, and constipation. Our patient is a 56-year-old man with history of hepatitis C and alcohol misuse disorder He was transferred to University Hospital (UH) from Boone Hospital with nausea, vomiting, and concerns of hypercalcemia. CT of the chest on day 5 revealed a large predominantly cystic lesion with tiny enhancing internal nodular components external to the inferior right lobe of the thyroid most likely representing a cystic parathyroid adenoma which was likely negative on nuclear medicine scan because of its cystic component (Figure 3). Impression: Large predominantly cystic lesion with tiny enhancing internal nodular components lying on the external aspect of the inferior right lobe of the thyroid most likely representing a cystic parathyroid adenoma.

Discussion

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Disclosures