Giant cystic parathyroid adenoma with thrombosis of internal jugular vein seen on CT and Tc-99m methoxy isobutyl isonitrile parathyroid scan
A 54-year-old female presented with 3 years history of bony pains, muscle weakness, fatigue, and depression with soft tissue swelling over left thyroid bed and left upper limb. Serum calcium and parathormone levels were abnormally high (17.4 mg/dl and 1182 pg/ml, respectively). Tc-99m MIBI scan revealed a large area of non-homogenous tracer uptake over left thyroid bed and superior mediastinum displacing the thyroid toward right []. In view of raised serum calcium and parathormone levels, it was considered a cystic parathyroid adenoma as non-functional (true) parathyroid cysts are also a known entity.[] An associated cold defect has been reported in patients with cytsic parathyroid adenoma.[] Cytic adenomas have been reported to occur in hypercalcemic crisis as the result of acute necrosis or hemorrhage of a parathyroidadenoma.[]\nComputed tomography scan showed a large left-sided parathyroid adenoma with marked cystic changes and thrombosis of left internal jugular vein []. Cystic degeneration of parathyroid adenoma is reported in 1-2% cases with primary hyperparathyroidism,[] and 4% of abnormal parathyroid glands.[] Thrombosis of left internal jugular vein has been reported in few case reports.[] Excisional biopsy revealed cystic parathyroid adenoma with no evidence of malignancy.