Do giant parathyroid adenomas represent a distinct clinical entity?

Abstract

Background The size of abnormal parathyroid glands in patients with primary hyperparathyroidism is highly variable, but the clinical significance of giant glands is unknown. Methods 300 consecutive patients were reviewed following parathyroidectomy for primary hyperparathyroidism. We compared patients with giant parathyroid adenomas (weight ≥95th percentile) with the remaining patients. Results Giant adenomas were defined as weight ≥95th percentile or 3.5 grams (median 0.61 g, range 0.05–29.93). Patients with giant adenomas had a higher mean preoperative calcium level, higher mean parathyroid hormone level, and were less likely to have multiglandular or symptomatic disease. Giant adenomas were successfully localized on imaging in 87% of patients, which was not significantly increased over other patients (82%). There were no differences between the groups in age, gender, gland location, or the incidence of persistent or recurrent hyperparathyroidism. Finally, giant glands had an increased incidence of symptomatic post-operative hypocalcemia including one patient who required rehospitalization following removal of a giant gland. Conclusions Giant parathyroid adenomas have a distinct presentation characterized by single gland disease and lower incidence of symptoms despite increased levels of calcium and parathyroid hormone. Additionally, following resection of a giant adenoma, patients are more likely to develop symptomatic hypocalcemia.

Radiological considerations and surgical planning in the treatment of giant parathyroid adenomas

“…1 Pathological parathyroid glands, excised from patients with pHPT, show great variability in size and have a median estimated weight of 650mg. 3 The term 'giant parathyroid adenoma' is used in the literature to describe sporadic cases of parathyroid adenomas with a glandular mass greater than the median estimated. Various weight cut-offs have been used, the largest being 3.5g.…”

“…3 Patients with giant parathyroid adenomas were more likely to have single gland disease as well as greater mean preoperative calcium and PTH levels compared with those with non-giant adenomas. No differences were recorded with regard to gland location, accuracy of imaging modalities, or persistent or recurrent pHPT.…”

“…2 Spanheimer et al concluded that giant parathyroid adenomas might represent a distinct clinical entity. 3 Indeed, in a study published by Sulaiman et al in 2012, the genetic characterisation of sporadic parathyroid adenomas weighing >4g revealed specific genomic features that correlated positively with PTH levels and therefore parathyroid hyperfunction. 4 The present case was that of a true giant parathyroid adenoma, both in terms of its size and weight, associated with severe hypercalcaemia and extremely high PTH levels.…”

Challenging neck mass: non-functional giant parathyroid adenoma

“…Spanheimer et al 11 referred to giant adenomas as a distinct clinical entity. They tried to characterise the patients with giant parathyroid adenoma and compared them with other patients with pHPT; they concluded that ‘giant adenomas present with increased serum calcium and PTH levels and have higher rate of asymptomatic disease’.…”

“…Giant adenomas are defined as weighting ≥95th centile or ≥3.5 g11 and virtually all of them are PTH-secreting.…”