A Novel Way to Look at Hypercalcemia- a Case Report of Atypical Parathyroid Adenoma

Presentation Number: MON 312
Date of Presentation: April 3rd, 2017

Preethi Polavarapu* and Sann Yu Mon
University of Pittsburgh Medical Center, Pittsburgh, PA



Hypercalcemia can be due to PTH-mediated and non PTH-mediated causes. Parathyroid adenoma accounts for 85% of PTH-mediated causes. We are reporting a case of atypical parathyroid adenoma presenting as severe hypercalcemia.

Clinical case:

A 60-year-old African American male patient presented with progressive polydipsia, polyuria, nausea, constipation, and confusion. He was noted to have corrected serum calcium of 15 mg/dl (n- 8.5-10.2 mg/dl ), serum PTH 834 (n- 10-65 pg/ml), Vitamin D panel was 18 ng/ml (n-30-100). Hypercalcemia improved with intravenous fluid, Calcitonin, and IV Zolendronate. Parathyroid SPEC-CT study revealed definite hyperfunctioning tissue medial to the mid-upper aspect of the left thyroid lobe, within the left tracheoesophageal groove, measuring up to 3.5 cm in caudal cranial dimension. Subsequently, he underwent surgery to remove left superior parathyroid gland and Thymus. Intraoperative PTH dropped to 54 pg/ml. Surgical pathology reported atypical parathyroid adenoma based on findings of enlarged hypercellular parathyroid with fibrosis, no vascular invasion, perineural invasion, infiltration.


This is the first case report of atypical parathyroid adenoma presenting as severe hypercalcemia. The differentiation of parathyroid adenoma and carcinoma based on their clinical and histopathological has been a challenge. One study suggested that patients with parathyroid carcinoma were found to have higher blood calcium levels (>/=14 mg/dL in 16 of 26 patients [62%]), whereas only 1 of 6 patients with atypical adenoma (17%). According to the histopathological classification of the World Health Organization, atypical parathyroid adenoma is defined as a parathyroid tumor that does not show locally advanced growth or metastases. However, it may show cell atypia, fibrotic tissue, trabecular growth, fibrotic capsular involvement, and increased mitotic rate. Histology of parathyroid CS including thick fibrous bands, mitotic activity, and vascular and capsular invasion.


Nothing to Disclose: PP, SYM