Right neck mass; growing for 5 months. In the right anterior neck, there is a well-circumscribed, multilobulated mass, which measures transaxially 3.4 cm x 2.8 cm while craniocaudally measures 4.1 cm. The mass is T2 hyperintense and mildly T1-hyperintense. Following contrast injection, there is laterally nodular but otherwise thin uniform rim contrast enhancement. The mass extends from just inferior to the right submandibular gland, which is mildly deformed but not invaded by the mass, reaching inferiorly to the right thyroid lobe with no clear separation between the two. The mass is located just deep to and inseparable from the right-sided strap muscles. It causes mass-effect on the adjacent trachea and larynx causing mild-to-moderate airway narrowing. The mass also posteriorly displaces the right carotid sheath contents, without vessel narrowing, as well as the anterior margin of the sternocleidomastoid muscle. There is no active inflammation in the adjacent tissues. There are multiple mildly prominent lymph nodes in both sides of the neck, including lateral retropharyngeal lymph nodes, which is a common finding in this age group. There is no mass within the major salivary glands. There is no other mass in the thyroid gland.Cervical spine and included brain are unremarkable.
Cystic anterior right neck mass, closely related to the right thyroid lobe and the strap muscles with differentials including thyroglossal duct cyst and lymphatic malformation. Location is not typical for brachial cleft cyst. Intrinsic T1 hyperintensity within the cyst and mildly nodular rim of contrast enhancement may be related to prior hemorrhage or infection. 