Recurrent High-Flow Arterio-Venous Malformation of the Thyroid Gland

Background: Vascular malformations and hemangiomas of the thyroid gland are rare disorders. The first case of a patient with recurrent high-flow arterio-venous malformation of the right thyroid gland involving the right endolarynx is presented. Patient findings: In June 2013, a 42-year-old female patient presented to the surgical department with recurrent hoarseness and a soft, vibrating mass on the right side of her neck. In 1993, she underwent right subtotal hemithyroidectomy with embolization on the day before surgery for a high-flow arterio-venous malformation of the thyroid gland. Diagnostic work-up in 2013 demonstrated a complex recurrent high-flow arterio-venous malformation on the right side of her neck involving the endolarynx. Full function of the right vocal fold could not be ascertained. The lesion was embolized again and excised the following day. Intraoperative gross bleeding and scar tissue prevented visualization and monitoring of the recurrent laryngeal nerve. Gross bleeding was also noted on hemithyroidectomy after embolization in 1993. No therapy was needed for the endolaryngeal part of the lesion. Histology showed large arterio-venous malformations with thyroid tissue. She remains well without signs of recurrence 18 month later but with a definitive voice handicap. Summary: This is the first report of a recurrent high-flow arterio-venous malformation originally developing from the right thyroid gland involving the right endolarynx. Counseling, diagnostic, and therapeutic work-up of the patient was possible only with an interdisciplinary team. The endolaryngeal part of the hemangioma dried out after embolization and completion hemithyroidectomy. Her hoarseness has greatly improved but a definitive voice handicap remains. Conclusion: High-flow arterio-venous malformations of the thyroid gland are a rare disease, and recurrent lesions have not been reported. Interdisciplinary management of these patients is mandatory due to the complex nature of the underlying pathology. Recurrence might develop after long free intervals.