Endocrine Abstracts

Introduction: The most common localization of parathyroid glands is behind the thyroid gland poles. According to different authors ectopic localization is present in 37–45.7%.

Case report: Caucasian male, 31 years old, with elevated serum calcium was sent to an endocrinologist after pyelolithotothomy. He has the history of ulcerative colitis treated with anti-inflammatory therapy. Laboratory analysis: total serum calcium: 2.85 mmol/l, phosphorus: 0.63 mmol/l, alkaline phosphatase: 137 J/l, parathyroid hormone (PTH): 114 pg/ml, osteocalcin: 90.0 ng/ml, cross laps: 1447.0 pg/ml. Spine DXA T-score: −2.8; Z-score: −2.9. Laboratory analysis suggested diagnosis of primary hyperparathyroidism. Ultrasonography did not show enlarged parathyroid glands. Two-phase parathyroid gland scintigraphy (99mTc-MIBI) with SPECT of the thorax was done. The result was suggestive for the ectopic parathyroid adenoma localized in the anterior mediastinum. CT examination of the neck and thorax showed the formation of 12×12 mm in aorto-pulmonary window, along the pulmonary artery main stem, which could correspond to ectopic parathyroid glands. CT angiography of the thoracic aorta described oval soft tissue nodule 8 mm in diameter at the same location, which could correspond to ectopic parathyroid or lymph gland. The patient was referred to surgical treatment. Intraoperatively glandular formation ~1 cm in diameter was found in thymic tissue in upper anterior mediastinum. Ex-tempore and further patohistological analysis confirmed intrathymic parathyroid adenoma. Substitution of calcium and vitamin D was introduced until achieving normal levels of serum calcium and PTH levels (total calcium: 2.50 mmol/l, PTH: 36.3 pg/ml). Other controls in the same period: osteocalcin: 13.13 ng/ml, cross laps: 108.9 pg/ml, DXA of the spine after 13 months T-score: −1.3; Z-score: −2.0.

Conclusion: This case is presented because of relatively rare localization of parathyroid gland adenoma.