Giant versus regular parathyroid adenoma: A retrospective comparative study

A fraction of Parathyroid Adenoma (PTA) is considered giant if they weigh more than 3.5 g. There is no clear consensus whether this subgroup has a distinct clinical or biochemical presentation that could have implications on PTA localization and management. In this study, we investigate the difference between regular and giant PTA patients regarding their clinical and laboratory findings as well as their postoperative outcomes.

Clinical and PTA-related data were retrospectively retrieved from all patients undergoing parathyroidectomy from 2010 to 2019 at our hospital.

A total number of 84 PTA (Females 76.2%) patients were included, of which 24 (28.6%) qualified as a giant with a mean weight of 7.86 g and the rest were regular adenomas (71.4%) with a mean weight of 1.45 g. Giant adenomas were more likely to present at a younger age compared to regular adenoma patients, (44.4 vs 50.8, P = 0.053, D = 0.470). Preoperative PTH levels were significantly higher in the giant PTA group (650.8 vs 334.2 pg/mL, P = 0.044, r = 0.22). Hospital stay was on average 1.6 days longer in giant PTA patients compared to regular PTA patients.

Giant PTA compromised a significant percentage of all adenomas, which was higher than what is reported in the literature and might reflect a delay in diagnosis and lack of screening tests. Both giant and regular adenomas seem to run a similar clinical course, yet biochemical abnormalities in PTH levels may have a predictive value for adenoma weight.