Endocrine Abstracts

This is a case of a 48-year-old lady initially referred to respiratory clinic with symptoms of breathlessness. She had a high-resolution CT thorax where an incidental finding of a right para-oesophageal 2.4-cm soft tissue density at the level of the thyroid gland identified. A CT neck was performed for further evaluation again showed the soft tissue mass (26 mm×37 mm) situated to the right of the oesophagus and another mass (16 mm×26 mm) left of the oesophagus. Discussion at the Lung MDT felt they may represent thyroid nodules but given location and relative normality of the rest of the thyroid parenchyma, parathyroid adenomas were possibilities hence she was referred to the endocrine surgeon. She then described symptoms of irritation in her throat on swallowing over the previous 6 weeks but no subsequent breathing problems. On neck examination, the thyroid lobes were just palpable, with no cervical lymphadenopathy. She was clinically and biochemically euthyroid with a normal calcium and parathyroid hormone level. Ultrasound thyroid reported hypoechoic heterogenous solid masses posterior to the thyroid; 3 cm on the right and 2 cm on the left. These masses appeared separate from the thyroid with minimal internal vascularity, likely representing parathyroid adenomas. MRI soft tissue neck could not differentiate between parathyroid and thyroid origin. Following Endocrine multi-disciplinary team discussion, the patient had a thyroid technetium scan and technetium MIBI scan with findings concordant that it was probably thyroid in origin rather than parathyroid adenomas. Endoscopic fine needle biopsies found small foci of follicular tissue with immunochemistry showing strong nuclear positive staining with positive thyroglobulin antibodies, suggesting thyroid tissue, not parathyroid.

Conclusion: This case highlights the difficulty differentiating between thyroid and parathyroid masses found incidentally. Dedicated imaging and biopsies may be the only way to confirm the nature of these masses.