P109\u2005An unusual case of an antenatal diagnosis of huge neck mass; a thyroid immature teratoma in a newborn

Abstract

Introduction Head neck teratomas are rare benign tumors consisting of 3–5% of all teratomas (1,2). Teratomas are embryonal neoplasms that arise when totipotential germ cells escape the developmental control of primary organizers and give rise to more or less organoid masses in which tissues derived from all three blastodermic layers (ectoderm, endoderm, and mesoderm) can be identified. Their histologic features are therefore heterogenous and may include cystic or solid areas with organoid patterns as well as mature or immature components. Case description We report a case of an antenatal diagnosis of a huge neck mass on antenatal ultrasound and fetal in utero MRI at 33 weeks gestation. He was born by ELSCS at 38 weeks gestation and an endocotracheal intubation was performed directly to maintain airway. The MRI neck postnatal confirmed a well circumscribed multicystic and solid anterior neck mass 9.7x5.2x4.9 cm. Surgical resection of the mass and thymectomy were done on day 2 after birth. The thyroid gland was not identified surgically. A single parathyroid gland was identified intraoperatively and preserved. The pathology report of the neck mass confirmed immature teratoma arising within and largely effacing the thyroid gland. No malignant germ cell tumour elements identified. He required levothyroxine treatment to replace the thyroid function. Hypocalcaemia developed postsurgical likely as a result of hypoparathyroidism. He was therefore managed by one alpha and calcium supplements to maintain normocalcaemia. He is feeding orally and continues to show appropriate normal growth and development. Discussion Cervical teratomas in children are almost always benign but locally are aggressive. They can present with respiratory airway compromise and excision is required. A multidisciplinary management is needed with multiple specialties involvement. If complete thyroid tissue is removed replacement therapy is required post operatively. Risk of hypocalcemia secondary to hypoparathyroidism developing post operatively should be monitored and treated accordingly. References Rothschild MA, Catalano P, Urken M, Brandwein M, Som P, Norton K, Biller HF. Evaluation and management of congenital cervical teratoma. Case report and review. Arch Otolaryngol Head Neck Surg. 1994;120(4):444–448. Lack EE. Extragonadal germ cell tumors of the head and neck region: review of 16 cases. Hum Pathol. 1985;16:56–64.