Mediastinal parathyroid cyst: A case report and review of the literature.

Mediastinal parathyroid cysts (MPCs) are extremely rare, benign lesions arising from the parathyroid glands and residing within the thoracic cavity. This study aims to advance understanding of MPC, emphasizing accurate diagnosis and management approaches for this rare condition. A 46-year-old woman presented with dysphagia for one week. Blood tests revealed elevated parathyroid hormone (PTH) (112.8 pg/mL) and normal serum calcium (9.54 mg/dL). Ultrasonography identified a large, well-defined cystic nodule measuring 46 × 30 × 25 mm, extending retro-sternally in the right upper third of the chest. A subsequent high-resolution computed tomography scan of the chest revealed a large space-occupying lesion (47 × 43 × 31 mm) in the superior mediastinum, near the esophagus, suggesting an esophageal duplication cyst or, less likely, a bronchogenic cyst. Video-assisted thoracoscopic surgery (VATS) was performed, and the entire cyst was excised, confirmed histologically as a mediastinal parathyroid cyst. Mediastinal involvement of PCs poses diagnostic challenges due to their rarity and diverse clinical presentations. Surgical excision is necessary for symptomatic cases, with VATS emerging as a favorable approach.