Endocrine Abstracts

Introduction: Primary Hyperparathyroidism (pHPT) is a calcium metabolism disease, resulting from one or more parathyroid glands hyperfunction. Ultrasonography and Technetium Sestamibi are, nowadays, the first line imaging techniques for diagnosis. Recently, a 4-dimensional computed tomography (4D-TC) protocol has emerged, presented in the last endocrine surgery guidelines. It is a dynamic imaging exam based on the parathyroid contrast uptake pattern, whose sensitivity and specificity have been shown to be superior to conventional imaging tests. 4D-TC allows a better anatomic, morphologic and functional precision for detection of parathyroid lesions either of typical or ectopic location.

Clinical case: 76 years-old man, with history of arterial hypertension, renal microlithiasis and prostate neoplasm, evaluated in endocrinology department for nodular thyroid disease and osteoporosis. In routine laboratory test, it was detected hypercalcemia (11.3 mg/dl), normal phosphatemia (2.6 mg/dl), elevated parathormona (PTHi 169.2 pg/ml), normal creatinine (1.1 mg/dl) and normal 24 h urinary calcium level. Either, ultrasonography and Sestamibi were negative for parathyroid lesions. Because of the presence of three surgery criteria (hypercalcemia, osteoporosis and renal lithiasis), it was decided to perform a preoperative 4D-TC, which revealed a parathyroid adenoma in the lower third of right thyroid lobe with 9×20 mm. A parathyroidectomy was performed without complications and intraoperative PTHi levels vary from basal value of 164.9 pg/ml to 55 pg/ml after procedure. The histologic report confirmed parathyroid adenoma. Last analytical evaluation showed maintained normal serum values of calcium (9.4 mg/dl) and PTHi (70 pg/ml).

Discussion: This clinical case portrays a pHPT diagnosis in which only the 4D-TC, allowed the identification and location of the underlying lesion, after conventional first-line imaging tests were negative. It was our purpose, to demonstrate the potential of 4D-TC as an effective method to identify parathyroid lesions, especially in cases of difficult detection, constituting a useful tool in the preoperative evaluation. Its use, replacing conventional exams, may happen if more studies confirm its diagnostic superiority.