Primary schwannoma of the thyroid gland presenting as an asymptomatic cold nodule.

Schwannomas are benign neoplasms that may arise from Schwann cells of the nerve sheath all over the body. Although schwannomas of the head and neck region are common, the thyroid gland is a rare site for schwannomas, with little documentation in the literature. Presented is a case of a 57-year-old woman who was evaluated in our outpatient clinic for hypothyroidism because of Hashimoto thyroiditis. Thyroid ultrasound revealed a single prominent nodule, which was cold on technetium Tc 99m thyroid scan. Fine needle aspiration of the nodule had aroused suspicion for malignant thyroid neoplasm. Complete thyroidectomy was undertaken without complications. Microscopic examination and immunohistochemical stains supported the diagnosis of a primary thyroid schwannoma.