Endocrine Abstracts

Introduction: Parathyroid hyperplasia is the second cause of primary hyperparathyroidism (PH), representing 15–20% of all cases. The scintigraphy with Tc-99m-Sestamibi is a preoperative exam used to identify parathyroid adenomas or hyperplasia. It has a sensibility of 50–90%, which increases with larger parathyroid size. The neck ultrasonography (US) has also an important role detecting parathyroid enlarged glands with 70% sensibility. We report a case of parathyroid hyperplasia where the imaging exams fail to detect a 40 mm parathyroid.

Case report: 75-year-old woman with osteoporosis, spontaneous bone fracture and osteoarticular pain. Laboratory evaluation showed a parathormone (PTH) of 145 pg/ml (range 14–72), a serum calcium of 12,0 mg/dl (range 8,6–10,2) and a phosphorus of 2,2 mg/dl (range 2,5–4,5). A neck US was performed revealing a 17 mm hypoechogenic vascularised nodule consistent with the inferior left parathyroid, also visible in the Tc-99m-Sestamibi. Patient was submitted to inferior left parathyroidectomy. The intraoperative exploration conducted to the additional finding of an enlarged superior right parathyroid with 40 mm also removed. The final diagnosis was nodular hyperplasia of both glands. Retrospectively, a detailed familial history was taken and considered negative for hyperparathyroidism and/or endocrine tumours. After 2 months post surgery, the patient is under Vitamin D and Calcium and mentioned improvement in symptoms.

Conclusion: Coincidental results of an anatomic exam (US) and a functional one (Tc-99m-Sestamibi), suggesting the involvement of a single gland, do not exclude pluriglandular HP. Vitamin D and Calcium were started considering the bone disease; discontinuation and tapering of therapy will be managed according to calcium and PTH levels.