Oxyphil Cell Parathyroid Adenomas Causing Primary Hyperparathyroidism: a Clinico-Pathological Correlation.

Area of Science:

• Endocrinology
• Pathology
• Surgical Oncology

Background:

• Oxyphil cell parathyroid adenomas (OPAs) were historically considered rare and clinically silent causes of primary hyperparathyroidism (PHPT).
• Clinical observations suggest OPAs may present more frequently and with a more severe form of PHPT than classical adenomas.

Purpose of the Study:

• To determine the incidence of OPAs.
• To describe the clinical presentation of OPAs.
• To compare the clinical characteristics of OPAs with classical parathyroid adenomas.

Main Methods:

• An observational case-control study was conducted over an 11-year period (2002-2012).
• Histopathology slides from 2739 patients undergoing parathyroidectomy for PHPT were reviewed to identify OPAs (>75% oxyphilic cells).
• A control group of 91 patients with classical or non-oxyphil adenomas was age- and sex-matched.

Main Results:

• 91 OPAs were identified, showing higher preoperative serum calcium and parathyroid hormone (PTH) levels compared to controls.
• OPA cases had a lower proportion of asymptomatic disease at presentation (15% vs. 29%) and a trend towards higher rates of renal calculi.
• Preoperative ultrasound localization accuracy was lower for OPAs than for classical adenomas.

Conclusions:

• Oxyphil cell parathyroid adenomas are frequently symptomatic and associated with more severe primary hyperparathyroidism.
• Higher serum calcium and PTH levels are characteristic of OPAs.
• OPAs pose diagnostic challenges due to less accurate preoperative localization by ultrasound.