Daily Radiology Case

Explanation

This is an ectopic parathyroid adenoma in the anterior mediastinum. The inferior parathyroid glands develop alongside the thymus and descend with it, so a small number end up in the chest rather than behind the thyroid. When one becomes an adenoma it can raise parathyroid hormone while calcium stays normal, which explains the earlier eucalcaemic hyperparathyroidism and the clean neck ultrasound. A technetium-99m sestamibi scan confirms it, as the adenoma retains tracer while normal tissue washes out, and SPECT/CT then pinpoints the location, here between the second and third right sternocostal joints. Treatment is surgical excision, which was carried out in this case.

Source: Vélez Parra G, Ectopic parathyroid adenoma. Case study, Radiopaedia.org (Accessed on 23 Jul 2026) https://doi.org/10.53347/rID-239940

Hints

• A 75-year-old woman is referred for further work-up after routine blood tests over several years reveal a quietly persistent hormonal abnormality.
• On examination her neck is entirely normal, with no palpable mass and no visible swelling.
• Blood tests show a raised level of the hormone that regulates calcium, yet her serum calcium sits comfortably within the normal range.
• A neck ultrasound is unremarkable, so a contrast CT of the chest is performed and reveals a small rounded soft tissue nodule sitting just in front of the great vessels.
• The gland at fault forms high in the neck during development but travels down alongside the thymus, so a small fraction come to rest far lower within the chest.
• A dedicated nuclear medicine scan shows the nodule taking up tracer and holding onto it long after normal tissue has cleared, marking this small mediastinal lesion as the overactive source.