[Changes in the clinical presentation of primary hyperparathyroidism. Analysis of 84 cases]

During the last two decades, the clinical presentation of primary hyperparathyroidism (PHP) has changed due to the routine use of multiphasic biochemical screening tests. We assessed 84 patients with PHP treated in our service between 1977 and 1991. The yearly incidence increased from 1.6 to 7.6 patients/year with the introduction of multiphasic biochemical testing in our hospital in 1982; likewise the proportion of asymptomatic patients increased from 12.5 to 40.7%. The most frequent presenting symptoms were bone pain and renal colic. Nineteen percent of patients were over 70 years old and this age group had distinct clinical features. The plasma chlorine/phosphorus ratio was abnormal in 95% of cases; on the contrary only 7 of 18 patients had a urinary calcium excretion over 300 mg/day. Cervical ultrasound, performed in 45 patients had a positive predictive value of 78% to localize the lesion. Bone density was below fracture threshold in 50% of studied patients. The principal surgical finding was the presence of adenoma. Twenty one percent of patients had symptomatic hypocalcemia during the first week after surgery; however, only 2.5% of patients continued to have hypocalcemia one month after surgery. One patient had an inferior laryngeal nerve damage and two a cervical hematoma. It is concluded that the introduction of massive calcium measurements has allowed an early diagnosis of asymptomatic PHP, specially in elderly people.