There is an asymptomatic group of patients with mild hyperparathyroidism which may not require surgery.
There have been multiple reports that these "asymptomatic" patients actually do have symptoms, and that these are relieved by surgery. This grand rounds reviews the current post. 

There are two groups of patients with hyperparathyroidism:

  1. Symptomatic patients - patients who present significant bone, renal, GI, or neuromuscular symptoms typical of hyperparathyroidism. These patients require surgery.
  2. Asymptomatic patients - patients without the classic signs or symptoms of hyperparathyroidism (i.e. osteitis fibrosa cystica, nephrolithiasis, peptic ulcer disease, pancreatitis, hypertension, gout). These patients may not require surgery.
Multiple studies show a high prevalence of subtle symptoms in "asymptomatic" patients. These include fatigue, weakness, depression, memory loss, personality change, exercise fatigue, back pain, polydipsia, polyuria, constipation, etc.
In a case-control study of 152 patients it was shown that the prevalence of these symptoms were statistically higher than in normal controls, and that parathyroidectomy relieved many of these subtle symptoms. Another study evaluated the prevalence of psychological symptoms in patients with "asymptomatic" hyperparathyroidism, with similar findings.
The effects of minimally symptomatic hyperparathyroidism on bone density has been recently reported. Silverberg followed 66 patients with hyperparathyroidism who did not meet NIH criteria for surgery for 6 years. They also followed 24 patients who did meet surgical criteria, but refused surgery. Although all patients had reduced bone mass compared to normal controls, there was no progression of their disease (i.e. no change in bone density, serum calcium, or PTH level, and no onset of any new symptoms). Additionally, they followed 34 patients who did meet NIH criteria for surgery, and did have surgery. They noted significant (4-13%) increase in bone density. McDermott gave patients with asymptomatic hyperparathyroidism estrogen, and noted an increase in bone density, nearly to normal levels. 

Summary of pros and cons for early surgery in patients with minimally symptomatic hyperparathyroidism: 

Against early surgery:

  • Calcium level is stable
  • Bone density is stable
  • Estrogen supplementation may be a therapeutic modality to treat osteoporosis
  • Renal function is stable
  • Most patients do not have signs or symptoms of disease progression

For early surgery:

  • Improved subtle symptoms
  • Substantially increases bone density
  • Increases muscle power
  • Very low risk of surgical complications (<5%)