Endocrine Abstracts

Introduction: A teratoma is a rare type of tumor deriving from the germ layer cells (ectoderm, mesoderm and endoderm), typically benign, more frequent in infants. Adult onset teratomas are most commonly gonadal cell tumors. Extra--gonadal teratomas generally affect the midline, most frequently anterior mediastinum, retroperitoneum, pineal and suprasellar area. Head and neck teratomas are an extremely rare entity and represent only 0.47–6% of all cases.

Case report: Female patient, 70 years old, no relevant personal or familial history. Patient is followed in Endocrinology outpatient care due to to an heterogeneous, predominantly hypoechoic nodule, 25 mm in length, located in the right thyroid lobe. Given the nodule description the patient underwent a fine needle aspiration. The result suggested a follicular lesion of undetermined significance/atypia of undetermined significance. The fine need aspiration was repeated with an inconclusive result. The third fine needle aspiration revealed the presence of a proteinaceous, amorphous tissue, with numerous vacuoles and squamous cells compatible with a branchial cyst. Due to the appearance of compressive symptoms a CT cervical scan was ordered. The image exam showed the presence of a nodular lesion, 19 × 29 × 25 mm of well defined limits, heterogenous, with soft tissue, macroscopic fat and calcium fragments suggestive of a teratoma, causing tracheal and esophageal deviation, with no associated cervical adenomegalies. The patient was subjected to a right thyroid lobectomy. The pathological analysis revealed a pseudo-encapsulated nodule, occupying nearly all of the right thyroid lobe, with 30 mm of long axis, compatible with a cystic mature trigerminative teratoma, composed exclusively by well differentiated elements (grade 0).

Discussion: Thyroid teratomas represent less than 0.1% of all primary thyroid tumors. These lesions typically present as cystic or mixed lesions and the cytological result might be inconclusive. Despite being more frequent in children, teratomas do not spare any age group.