Bilateral multifocal water-clear cell parathyroid adenoma: A case report with literature review

Water-clear cell parathyroid adenoma (WCCPA) is an exceptionally rare subtype of parathyroid adenoma characterized by large, clear, glycogen-rich cells. A small number of cases have been reported in the literature. This report presents a rare case of bilateral multifocal WCCPA in a young female. A 34-year-old female presented with generalized bone pain and fatigue. Laboratory evaluation revealed hypercalcemia (12.9 mg/dL) and markedly elevated PTH (488 pg/mL), consistent with primary hyperparathyroidism (PHPT). Neck ultrasonography and computed tomography identified bilateral inferior parathyroid lesions extending retrosternally. The patient underwent bilateral inferior parathyroidectomy, revealing four encapsulated nodules. Histopathological examination demonstrated water-clear chief cells arranged in lobules and sheets, confirming multifocal WCCPA. Postoperatively, PTH and serum calcium normalized. Review of eight published WCCPA cases (2016-2025) revealed a mean age of 58.8 years (range 34-80) and a male predominance (62.5%). Most cases (87.5%) presented with symptomatic PHPT. Imaging with ultrasound and Tc-99m sestamibi was frequently inconclusive, with false-negative results in about 50% of cases. All patients underwent surgical excision, resulting in complete biochemical normalization (100%). No recurrences were reported during follow-up periods up to 50 months. WCCPA is a rare but noteworthy cause of PHPT. Definitive diagnosis requires histopathological confirmation, and surgical management leads to excellent outcomes.