Endocrine Abstracts

Lipoadenoma is an uncommon benign lesión of the parathyroid gland (<1%) and it has most commonly described as non-functional, but also is a very rare cause of primary hyperparathyroidism. Since 1958 scientific literatura had described 54 cases all over the world and only six of that paratyroid lipoadenomas was extended into torax. A case of intrathoracic parathyroid lipoadenoma with hyperparathyroidism is described. A 69–year–old man was refered to our hospital for hypercalcemia and primary hyperparathyroidism. By that time he was asymptomatic and was only treated with enalapril 10 mg per day. Laboratory tests revealed hypercalcemia (11.7 mg/dl), hypercalciuria (24 h urine calcium = 574 mg/day), hypophosphatemia ( 2.0 mg/dl), elevated serum parathyroid hormone level (PTH = 284.8 pg/dl), low 25 hydroxy vitamin D (25 OH D = 9 pg/ml) and glomerular filtration rate (GFR) = 79 ml/min. Parathyroid technetium–99n sestamibi scintigraphy failed to detect increased activity in the right lower pole of the thyroid, and that abnormal lession was extending into the superior mediastinum. SPECT–TC showed a nodule 45 × 24 × 62 mm hyperfunctioning behind the right thyroid lobe and extended into medistinum.

The patient accepted the surgery, so the tumor was excised. His serum calcium flollowing successfull inferior right parathyroidectomy was 9.6 mg/dl. After surgery, serum Calcium and PTH normalized to 8.5 mg/dl and 41.7 pg/dl respectively.

The pathological diagnosis was parathyroid lipoadenoma with abundant adipose and nests of chief cells.