We observed several cases of patients who believed they were free of sympto
ms or signs of primary hyperparathyroidism (pHPT) preoperatively. reported
a change of complaints following parathyroidectomy (PTX). We, therefore, de
cided to examine a larger group of patients to discover if these findings w
ere incidental or of more general significance. The role of PTX in these pa
tients with asymptomatic pHPT remains controversial. In 1991 criteria were
defined at a NIH-consensus conference, according to which patients qualify
for either operative therapy or long term medical surveillance. Until now,
it was generally believed that the majority of asymptomatic patients would
never develop symptoms.
In a epidemiological cohort-study, the perioperative data of 582 consecutiv
e patients with pHPT, including 116 asymptomatic patients (20.9%), who unde
rwent parathyroidectomy between 1987 and 1998 were evaluated by uni- and mu
ltivariate analysis. At a median of 72 months postoperatively, all patients
underwent a planned follow-up which included a standardised, validated que
stionnaire, physical examination and laboratory investigations. Eighty-six
patients who were asymptomatic preoperatively were available for follow-up.
Only eight (9.3%) were definitely asymptomatic, 4.6% of the entire, repres
entative cohort. Postoperative improvement was reported in 81.4% of the "as
ymptomatic" patients. Multivariate analysis did not reveal a single or a se
t of preoperative measurements, that would allow to predict the retrospecti
vely definitely asymptomatic patient. PTX resulted in normocalcaemia in 98.
8% of preoperatively asymptomatic patients, with an operative morbidity of
1.2% and no mortality. Many apparently asymptomatic patients with pHPT will
only realise that they did in fact have preoperative symptoms in retrospec
t, following PTX. This study suggests that using an up-to-date definition o
f asymptomatic pHPT, there are only a small number of truly asymptomatic pa
tients and that these cannot be predicted preoperatively, as their symptoms
may become apparent only after PTX. "Asymptomatic" patients with pHPT may
share the same objective and subjective benefits from PTX as symptomatic pa
tients. They should be operated as soon as the diagnosis is established.