Primary Hyperparathyroidism
Primary hyperparathyroidism is often clinically occult
and does not differ from that seen in patients with mild
sporadic primary hyperparathyroidism. It has been
reported in 10–25% of patients with MEN2A, but is rarely
the first manifestation of this syndrome (15,16). Diagnosis is
established by detecting high concentrations of intact
parathyroid hormone in the presence of hypercalcemia,
usually after the third decade of life. Pathological findings
show chief cell hyperplasia involving multiple glands and
sometimes multiple adenomas. Annual measurement of the
serum calcium concentration and parathyroid hormone in
gene carriers is probably adequate for screening purposes,
and should begin by age 8 years for carriers of RET
mutations in exon 10 and 11 and by age 20 years for carriers
of other MEN2A RET mutations. The goal for MEN2
patients with primary hyperparathyroidism is to excise the
enlarged glands and to leave at least one normal parathyroid
gland intact. If the glands are all enlarged, a subtotal
parathyroidectomy or total parathyroidectomy with autotransplantation
should be performed