Abstract
Background: Primary hyperparathyroidism is the most common cause of hypercalcemia. It is more commonly seen in postmenopausal women, but can develop in younger individuals. Brown Tumors are an uncommon finding that can be seen in sever hyperparathyroidism. These bone findings are most often seen in the maxilla or mandible, though can affect any bone. Bone changes are reversible after parathyroidectomy.
Clinical Case: An 18 year old male with a PMH of nephrolithiasis presented with a two day history of flank pain and hematuria. Endocrinology was consulted for hypercalcemia and elevated PTH. He had a family history of nephrolithiasis in his maternal uncle and grandfather, but no known family history of hypercalcemia or thyroid cancer. He was not on any medications or supplements. His initial labs were significant for a calcium of 15.0, PTH of 644, and a Vitamin D 25 of 11.7. He had no known history of hypercalcemia. He was treated with aggressive hydration, 4mg of zometa, 30mg of sensipar and two doses of 200mg calcitonin, with improvement in his calcium levels. Imaging of the abdomen and pelvis revealed multifocal solid-cystic lesions in the right superior pubic ramus and the distal femur, with smaller enhancing lesions in the left subtrochanteric, consistent with Brown Tumors. SpectCT was obtained and significant for a 2.1 by 1.4cm lesion in the anterior superior mediastinum. His overall presentation was consistent with primary hyperparathyroidism secondary to an ectopic parathyroid adenoma. Due to his relative young age at presentation and degree of primary hyperparathyroidism, there was concern for MEN1 or possible parathyroid carcinoma. MRI of the pituitary was obtained and showed a 4mm microadenoma in the right side of the pituitary. Prolactin, thyroid hormones, IGF-1, plasma metanephrines and calcitonin were all within normal limits. CDC73, a genetic marker for parathyroid carcinoma, was negative. Genetic work up for MEN1 was also negative. Endocrine surgery was consulted and he underwent a resection of the ectopic parathyroid adenoma.
Discusion: Though most patients with primary hyperparathyroidism are asymptomatic, nephrolithiasis and Brown Tumors can be seen with more severe cases. It is important to rule out possible genetic causes for primary hyperthyroidism in patients with abnormal presentations, as it will change the overall long term management.
Giant Ectopic Parathyroid Adenoma of the Mediastinum Causing Primary Hyperparathyroidism - A Rare Case Report with Review of Literature
