Ectopic Parathyroid Adenoma Presenting as a Mediastinal Mass

Area of Science:

• Endocrinology
• Surgical Pathology
• Diagnostic Imaging

Background:

• Persistent hypercalcemia can be caused by parathyroid adenomas, which are typically found in the neck.
• Ectopic parathyroid adenomas, particularly in the anterior mediastinum, are rare but documented causes of hyperparathyroidism.

Observation:

• A 35-year-old male presented with abdominal pain and was diagnosed with acute necrotizing pancreatitis and hypercalcemia.
• Despite pancreatitis treatment, persistent hypercalcemia and elevated parathormone levels suggested hyperparathyroidism.
• Imaging revealed a superior mediastinal mass, initially misdiagnosed as cystic teratoma via Fine Needle Aspiration (FNA).

Findings:

• Technetium-99m sestamibi scan confirmed parathyroid tissue uptake in the right inferior parathyroid extending to the superior mediastinum.
• Surgical excision of the mediastinal mass confirmed it as a parathyroid adenoma.
• The patient's persistent hypercalcemia was attributed to the ectopic parathyroid adenoma.

Implications:

• This case underscores the necessity of including ectopic parathyroid adenoma in the differential diagnosis for mediastinal masses presenting with persistent hypercalcemia.
• Early and accurate diagnosis of ectopic parathyroid adenoma is crucial for managing hyperparathyroidism.
• Advanced imaging techniques like Tc-99m sestamibi scans are vital for localizing ectopic parathyroid tissue.