Normocalcemia with persistent increase of parathyroid hormone: a prospective study

Ectopic thymic parathyroid adenoma and vitamin D deficiency rickets: a 5-year-follow-up case report and review of literature

Sixteen patients with primary hyperparathyroidism presenting as rickets have so far been reported in the English literature. However, no report of an ectopic thymic parathyroid adenoma presenting as rickets has been published. We report a 14-year-old Caucasian American, wheelchair-ridden male who presented with signs and symptoms suggestive of vitamin D deficiency rickets subsequently confirmed by laboratory and radiological findings. Following the intramuscular administration of 125,000 U ergocalciferol (vitamin D2), he developed hypercalcemia with persistently elevated parathyroid hormone (PTH) levels suggestive of primary hyperparathyroidism. Sestamibi scan demonstrated significant uptake in the superior chest, without uptake at the normal parathyroid glands location. Surgical exploration revealed normal parathyroid glands and a thymic mass, which was removed and confirmed by pathology to be a parathyroid adenoma. With subsequent oral ergocalciferol solution and calcium carbonate therapies, the patient's symptoms resolved, blood chemistries normalized, and radiological evidence of rickets significantly improved. To our knowledge, this is the first case of an ectopic thymic parathyroid adenoma in a patient presenting with rickets. Our patient demonstrates that hyperparathyroidism-induced hypercalcemia may be masked by severe vitamin D deficiency. Prolonged treatment with ergocalciferol after removal of the parathyroid adenoma was necessary to normalize iPTH and replenish vitamin D store.

Reelevation of parathyroid hormone level after parathyroidectomy in patients with primary hyperparathyroidism: importance of decreased renal parathyroid hormone sensitivity

BACKGROUND

We hypothesized that impaired peripheral sensitivity to parathyroid hormone (PTH) may play a role in reelevation of PTH after successful operation for primary hyperparathyroidism (pHPT).

METHODS

Factors affecting reelevation of PTH were determined in 90 patients who underwent parathyroidectomy for pHPT. PTH/nephrogenous cyclic adenosine monophosphate ratio, as an index of renal resistance to PTH, was examined in relation to factors shown to influence reelevation of PTH.

RESULTS

Serum PTH levels were elevated above the upper limit of normal in 23 patients (26%) at 1 week and in 39 patients (43%) at 1 month after parathyroidectomy. These 39 normocalcemic patients with elevated serum PTH at 1 month after parathyroidectomy had a higher preoperative serum level of PTH and lower serum phosphate and 25-hydroxyvitamin D (25OHD) concentrations than those with normal PTH (n = 59). Elevated PTH and low 25OHD were shown by multivariate analysis to be significant predictors of reelevation of PTH. Renal resistance to PTH was higher in patients with vitamin D deficiency or renal insufficiency than in patients with normal serum vitamin D concentrations or normal renal function, and it increased according to increases in levels of PTH.

CONCLUSIONS

The mechanism of PTH reelevation in patients with pHPT after successful parathyroidectomy appears to be renal resistance to PTH.

Elevated serum parathormone level after "concise parathyroidectomy" for primary sporadic hyperparathyroidism

BACKGROUND

Cure after parathyroid exploration is traditionally assessed by serum calcium concentration 6 months postoperatively. Postoperative normocalcemic elevation of serum parathormone (PTH) level has been described but is of unclear significance.

METHODS

In a 6-year prospective study of outcomes in 380 patients undergoing initial parathyroidectomy for primary sporadic hyperparathyroidism, we measured intact serum PTH and calcium levels at more than 5 months. Those with normocalcemic high PTH levels were begun on oral calcium + vitamin supplements and monitored.

RESULTS

At more than 5 months postoperatively, normocalcemic elevation in serum PTH level occurred in 28% of patients, was more common after resection of double adenomas (P =.01), and predated the onset of recurrent hypercalcemia in 3 of 3 patients with unrecognized multiglandular disease. Although delayed treatment with calcium and vitamin supplements produced no clear benefit, patients who took such supplements from the date of surgery were much less likely to have an elevated serum PTH level more than 5 months later (P =.0005).

CONCLUSIONS

After successful parathyroid surgery, compensatory normocalcemic elevation in serum PTH level is frequent and may arise from dietary deficiency. Monitored supplemental intake of calcium and vitamin D appears to prevent or to normalize the condition in most patients. Patients with normocalcemic elevation in serum PTH level should receive evaluation for dietary deficiencies as well as follow-up for possible residual disease.

Normocalcemia with elevated parathyroid hormone levels after surgical treatment of primary hyperparathyroidism

BACKGROUND

Thirty percent of patients who undergo successful parathyroidectomy for primary hyperparathyroidism show unexplained elevated postoperative serum parathyroid hormone (PTH) levels despite normocalcemia.

METHODS

PTH levels were measured monthly in 97 patients for 6 months after parathyroidectomy. Renal function, 25-OH-vitamin D levels, serum alkaline phosphatase levels, osteocalcin, and bone densitometry were evaluated before and 6 months after surgery. PTH reactivity to calcium loading was tested at the sixth month.

RESULTS

Thirty patients had elevated PTH levels despite normocalcemia after parathyroidectomy. Before surgery, these 30 patients had higher PTH and creatinine levels, lower vitamin D levels, and more extensive bone involvement than those with normal postoperative PTH levels. In patients with normal renal function and normal vitamin D levels, postoperative PTH values correlated with preoperative PTH levels but not with bone disease.

CONCLUSION

In most cases, elevated PTH levels after surgery is an adaptive reaction to renal dysfunction or vitamin D deficiency. If no adaptive cause can be found, persistent hyperparathyroidism must be suspected.

Ultrasonically guided chemical parathyroidectomy in patients with primary hyperparathyroidism: a follow-up study

OBJECTIVE

We evaluated the long-term results in two different groups of patients with primary hyperparathyroidism treated with ultrasonically guided percutaneous ethanol (96%) injection into parathyroid tumours.

DESIGN

A prospective long-term follow-up (more than 6 months). Ethanol (96%) was injected under ultrasonic guidance into biopsy verified solitary parathyroid tumours. Basic treatment included a maximum of three treatments with an interval of about 1 month (group 1) or 1 week (group 2). Dose of ethanol was half the volume of the parathyroid tumour.

PATIENTS

Two different groups of patients with only one ultrasonically detected and biopsy verified parathyroid tumour were treated. Group 1 (n = 18) were treated regardless of the severity of the hyperparathyroid disease. Group 2 (n = 14) were selected for treatment either due to severe hypercalcaemic symptoms (n = 3), a high surgical risk (n = 5), or refusal of surgery (n = 6).

MEASUREMENTS

The volume of the parathyroid tumours was measured as half the product of maximum length, width, and depth. Blood tests included measurements of ionized calcium, total calcium and PTH.

RESULTS

In group 1, 12 of 18 patients (66%) could be followed more than 6 months. Follow-up ranged from 12 to 58 months (median 45 months). A significant decrease (P < 0.001) in serum concentrations of ionized calcium and total calcium was observed. Eight patients (44%) later underwent surgical parathyroidectomy. Injection therapy was regarded as successful in 10 of 18 patients (56%). In group 2, 11 of 14 patients (79%) were followed more than 6 months. Follow-up ranged from 18 to 50 months (median 39 months). A significant decrease (P < 0.001) in serum concentrations of ionized calcium, total calcium and intact PTH (1-84) was observed. Treatment was successful in 11 of 14 patients (79%). Two patients required parathyroid surgery. Re-examination with ultrasound showed a significant reduction in the volume of the treated parathyroid tumours. Fibrosis surrounding the parathyroid tumours was detected in eight of 10 patients who subsequently had operations. One patient from each group had a complication of a unilateral permanent vocal cord paralysis following injection therapy.

CONCLUSION

Partial or complete long-term remission of primary hyperparathyroidism can be achieved using ultrasound-guided chemical parathyroidectomy. However, the intervals between treatments should be short and the treatment should be reserved only for patients not fit for surgery.