Issue: February 2020
Disclosures: Lee and Vodopivec report no relevant financial disclosures.
February 18, 2020
4 min read

Horner’s syndrome may be unexpected complication after thyroid surgery

Issue: February 2020
Disclosures: Lee and Vodopivec report no relevant financial disclosures.
You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact

A 27-year-old woman with no significant medical history presented to our institution for management of her thyroid cancer. She was initially seen at an outside hospital where she was found to have a nodule in the left thyroid lobe and a metastatic node in the lateral neck, left level II.

The patient reported no radiation exposure to head or neck during childhood, but she had a positive family history of thyroid cancer in two paternal cousins, nontoxic multinodular goiter in her father and sister, hypothyroidism in her mother and hyperthyroidism in her maternal grandmother.

Danica M. Vodopivec

She was clinically and biochemically euthyroid without any compressive symptoms. The biopsy of the left thyroid nodule was rated as Bethesda category IV (follicular neoplasm), and the lymph node was consistent with metastatic papillary thyroid cancer.

Stephanie L. Lee

The patient underwent total thyroidectomy with central and left lateral neck dissection. The surgical pathology reported a 5 cm papillary thyroid cancer in the left lobe of the thyroid with lymphovascular invasion, microscopic positive surgical margins, with five of 59 positive lymph nodes (two left level IIA nodes, one Delphian node and two level VI nodes). Initial risk classification was determined as T3N1bM0, American Joint Committee on Cancer (AJCC) 8th edition stage 1, and intermediate American Thyroid Association risk. She was treated with 100 mCi of radioiodine-131 and currently has an excellent response to therapy.

Ocular, other complications

Figure 1: Horner’s syndrome after thyroidectomy. Upper: Patient noted anhidrosis of the left side of the face and vasodilation of the contralateral side on a hot day. Red arrows indicate the sharp midline demarcation of the vasodilation. Upper and lower panels: Ptosis and miosis. Note the elevated left eyebrow in the attempt to counter the left ptosis. Miosis of the left iris results in a smaller pupil in the left compared with the right eye.

Source: Images courtesy of Stephanie L. Lee, MD, PhD, ECNU. Reprinted with permission.

Four weeks after her surgery, the patient presented to our clinic. She reported left upper lid drooping and showed a recent picture with only the right side of her face flushed in a hot summer day (Figure 1, upper panel). She was confident that these findings appeared after her thyroid surgery. Besides a surgical scar in her neck, a physical exam was notable for left upper lid ptosis and anisocoria with the left pupil having a smaller diameter than the right (Figure 1, lower panel).


A complete neurologic examination confirmed otherwise normal cranial nerves. She did not develop other complications of thyroidectomy, such as bleeding, wound infection, vocal cord palsy or hypoparathyroidism. A postoperative neck ultrasound conducted in the clinic did not show any suspicious nodes, masses, hematoma or collection that could potentially compress the sympathetic trunk.

Horner’s syndrome

The patient was diagnosed with Horner’s syndrome, a disorder characterized by pupil constriction, eyelid drooping, eye protrusion and lack of sweating on one side of the face caused by damage of the ipsilateral cervical sympathetic chain. Vascular dilation on the other side of the face may or may not be present (Figure 1).

Horner’s syndrome was described in 1853 by French physiologist Claude Bernard and then by the Swiss ophthalmologist Johann Horner in 1869. Kappeler mentioned Horner’s syndrome as a complication of thyroid surgery in 1865, and Kaelin reported a case of the syndrome following thyroidectomy in 1915.

Figure 2: Diagram of nerves in relation to the thyroid. The cervical sympathetic ganglion (red) is located posterior to the thyroid gland. Abbreviations: RLN, recurrent laryngeal nerve; Vagus n., vagus nerve; Strap, strap muscle; SCM, sternocleidomastoid muscle; CA, carotid artery; IJV, internal jugular vein; C6, C6 vertebral body.

Horner’s syndrome as described in this case report is a very rare complication after thyroidectomy with fewer than 35 cases reported in the literature, and most cases occur after surgery for malignant thyroid glands associated with lymph node dissection or with surgery for large goiters with retrosternal extension.

The middle cervical ganglion and the sympathetic trunk lie posterior to the thyroid gland close to the inferior thyroid artery within the thyroid bed (Figure 2). This close anatomical relationship with the thyroid makes the sympathetic trunk and the middle cervical ganglion vulnerable during thyroidectomy, especially when performed with a central neck dissection for metastatic nodes.

The possible causes of Horner’s syndrome after thyroidectomy are surgical damage; postoperative hematoma compressing the cervical sympathetic chain; ischemia-induced neural damage caused during lateral ligature on the inferior thyroid artery trunk; lateral retractor stretching of the cervical sympathetic chain; damage to the communication between the cervical sympathetic chain and the recurrent laryngeal nerve during its identification; and the possible anatomic variation in which the recurrent laryngeal nerve gives off a communicating branch to the cervical sympathetic chain. A literature review shows a variable postoperative onset of Horner’s syndrome between 2 days and 1 week.


No resolution

It is estimated that 70% of patients with Horner’s syndrome after thyroidectomy will have permanent damage or incomplete recovery while the remaining 30% will completely recover between 5 to 15 months after surgery. Our patient has a persistent Horner’s syndrome 4 years after her thyroidectomy.

It is important for endocrinologists and thyroid surgeons to be aware of this uncommon complication to reduce the risk for this facial disfigurement during surgery. Keep in mind that a good history and physical examination are beneficial for early diagnosis and education of the patient with this complication.

Disclosures: Lee and Vodopivec report no relevant financial disclosures.