Horner syndrome as a postoperative complication after minimally invasive video-assisted thyroidectomy

RATIONALE Horner syndrome is an unusual complication after thyroidectomy. PATIENT CONCERNS We report a case of Horner syndrome in a 34-year-old female patient with Graves disease associated with papillary thyroid carcinoma who underwent left-side minimally invasive video-assisted thyroidectomy and neck dissection. DIAGNOSIS Horner syndrome was diagnosed based on left myosis, eyelid ptosis, and mild enophthalmos, which developed in the patient on postoperative day 2. INTERVENTIONS The patient was administered glucocorticoids and neurotrophic drugs on postoperative day 3. OUTCOME The symptoms of Horner syndrome were significantly relieved 1 year later. LESSONS Surgeons must be aware that Horner syndrome may be a source of iatrogenic complications, and patients also should be informed of these complications before surgery.