Incidentally discovered parathyroid lipoadenoma in thyroid surgery: A case report and review of the literature

Parathyroid lipoadenoma is a rare type of parathyroid adenoma, described as a single parathyroid adenoma with more than 50% fat on histologic examination and an unknown etiology, which is one of the rare causes of primary hyperparathyroidism. The difficulty of parathyroid lipoadenoma is mainly diagnosed by preoperative imaging localization. We hope to arouse attention to the parathyroid adenoma which is difficult to locate through our case report. The patient was a middle-aged male with a body mass index of 38.4 kg/m² who admitted to our hospital with a 40-day history of an untreated thyroid nodule. We incidentally discovered parathyroid lipoadenoma in his thyroid surgery. His prognosis was good, and there were no signs of recurrence at his 12-month follow-up appointment. We believe that parathyroid lipoadenoma needs to rely on paraffin pathology to make a final diagnosis. This case report serves as a reminder that parathyroid lipoadenomas are also possible in patients who do not have primary hyperparathyroidism preoperatively and who have negative imaging. Clinicians must carefully examine the adipose tissue for the presence of parathyroid lipoadenomas during thyroid surgery to avoid postoperative hypoparathyroidism and persistent hypocalcaemia.