Chyle leak as a cause of neck swelling following a right hemithyroidectomy for multinodular goitre

Chyle leak (CL) secondary to inadvertent thoracic duct injury (TDI) is an exceptionally rare complication of a right hemithyroidectomy. TDI occurs in 0.5-1.4% of patients undergoing a thyroidectomy, and of those, only one-fourth are attained following right-sided neck surgeries, as the terminal thoracic duct (TD) typically terminates in the left side of the neck. Anatomical variations of the terminal TD are well renowned, and a right-sided terminal TD has been previously described. Although CL following right-sided neck dissection has been described in the literature, to our knowledge, this is the third case to describe a CL following a right hemithyroidectomy alone.We present a man in his 70s who was referred to endocrinology with a persistently low T4 on a background of normal Thyroid Stimulating Hormone(TSH). Incidentally, he was found to have a bilateral large goitre associated with chronic dyspnoea and dysphagia. He was planned for a total thyroidectomy; however, due to intraoperative difficulties, he underwent a right hemithyroidectomy only. Four days later, he re-presented with neck swelling and breathlessness. Re-explorative surgery identified serosanguinous fluid which later tested positive for chylomicrons, confirming a CL, likely from a right-sided terminal TD. Generally, he demonstrated a good response to conservative treatment.Complex anatomical variations of the TD exist and thus CL should be well-recognised as a differential diagnosis of neck swelling following both left-sided neck and right-sided neck surgeries. Head and neck surgeons should consider consenting patients undergoing right-sided neck surgeries for a CL.