An accessory thyroid gland that presented tumor-like images.

A 26-year-old woman presented with right breast pain and itching. Incidentally, a firm, non-tender, movable mass (3 cm in diameter) located in the lower right part of the neck was identified by palpation. Ultrasonography revealed a clearly demarcated dumbbell-shaped mass with homogenous hypo- (cranial side) and hyper-echogenicity (caudal side) compared with the thyroid gland. Computed tomography scan and magnetic resonance imaging presented images that were different from thyroid gland substance. The right thyroid lobe was strongly compressed by the mass. Hyperparathyroidism was ruled out by laboratory testing. The patient solicited resection of the mass despite recommendations for core needle biopsy, and it was removed surgically. The mass was surrounded by a thin capsule and was not connected with the thyroid gland. Pathological examinations revealed normal thyroid gland tissue. The final diagnosis was an accessory thyroid gland. Accessory thyroid glands should be considered as a possible diagnosis when nodules around the main thyroid gland are encountered.