Subclinical Forms of Primary Hyperparathyroidism
Author: Boyanov, Mihail A.
Clinic of Endocrinology and Metabolism, University Hospital “Alexandrovska”, Department of Internal Medicine, Medical University, Sofia
Abstract: Primary hyperparathyroidism (PHPT) was described in the 19th century as a disease of “stones, bones and moans”. The classical clinical picture of PHPT may include different combinations of typical skeletal, renal, gastro-intestinal and neuro-muscular signs and symptoms. The classical forms are known to be a rare disease. With the introduction of serum calcium measurements in the second part of the 20th century hypercalcemia became the landmark of PHPT. A new form of PHPT was identified – namely an oligo- or asymptomatic one in the presence of mildly elevated serum calcium. This form was described in up to 1-2 % of postmenopausal women with osteoporosis. The introduction of serum PTH measurement techniques allowed the identification of a third even milder form of the disease, namely the asymptomatic and normocalcemic presentation. This form might be viewed as the earliest stage of PHPT. It progresses very slowly over time and might remain steady for up to one or two decades. The cornerstone in the diagnosis is the abnormal proportion of serum PTH and serum calcium. The importance of imaging techniques for the localization of possible parathyroid adenomas grows in the setting of asymptomatic and normocalcemic forms. The classical treatment strategy, surgical removal of the hyper-functioning parathyroid glands, is nowadays replaced by a “wait-and-see” approach. The various aspects in the diagnosis and treatment of this particular subclinical form of PHPT are discussed.
Key words: parathyroid glands; primary hyperparathyroidism; asymptomatic forms; diagnosis; treatment