Giant parathyroid adenoma: a case report

BACKGROUND: Giant parathyroid adenoma is a type of parathyroid adenoma weighing > 3.5 g and having a size of more than 2 cm. CASE PRESENTATION: This report describes giant primary parathyroid adenoma with reference to the literature. We report the case of a 48-year-old Persian man referred to the clinic with knee and lower back pain. He had a history of mitral valve replacement and several episodes of bilateral nephrolithiasis. After a thorough assessment, a neck mass with a possible thyroid origin was detected, but further assessment showed it was of parathyroid origin. The resected mass was 9 × 6× 4 cm and weighed 122 g, and histopathology showed a giant parathyroid adenoma. CONCLUSION: Giant parathyroid adenomas that weigh more than 110 g and are larger than 8 cm can lead to significant hypercalcemia. Despite giant parathyroid adenomas and high parathyroid hormone levels, a calcium crisis may not always occur in these patients, and the masses may be initially misdiagnosed as a thyroid mass.