Parathyroid Cyst and Micropapillary Thyroid Carcinoma: A Case Study of Unexpected Concurrent Endocrine Pathologies

Parathyroid cysts (PCs) are rare tumors that predominantly affect middle-aged women and are characterized by symptoms of hyperparathyroidism, including fatigue, bone pain, and gastrointestinal issues. Management typically involves surgical resection due to their potential to cause profound hyperparathyroidism and hypercalcemia. PCs occasionally coexist with thyroid malignancies, including micropapillary thyroid carcinoma (MPTC), although the pathophysiological link between PCs and thyroid cancers remains unclear. We present a case of a 62-year-old woman with symptomatic hypercalcemia and a large cystic mass adjacent to the left inferior thyroid pole, initially suspected to be a PC. Preoperative imaging, including an ultrasound (US) and sestamibi scan, guided surgical intervention, resulting in en bloc resection of the PC along with a left hemithyroidectomy. Pathological examination confirmed the presence of both a PC and MPTC, raising the question as to whether there is a possible correlation between primary hyperparathyroidism (PHPT) and thyroid malignancy. This report aims to highlight the current PC management protocol, underscore the importance of thorough diagnostic evaluation and surgical strategies in addressing concurrent parathyroid and thyroid pathologies, and explore potential pathophysiological connections between these conditions.