Findings:
Correlating to the CT study a left cervical level IVa mass lesion measuring approximately 2 x 2.2 x 4.2 cm is seen, displacing the left common carotid artery and internal jugular vein anteriorly. The lesion compresses the internal jugular vein. It is isointense to muscle on T1-weighted MR images and hyperintense on T2-weighted images with small areas of low signal intensity, but no obvious flow voids. It shows avid enhancement on the postcontrast study. On the TWIST angiography it shows avid enhancement, similar to that of the thyroid gland.
The left thyroid lobe is enlarged, showing a heterogeneous, partially cystic and calcified nodule measuring approximately 3 x 2.5 x 3.5 cm, which extends to the anterior mediastinal with mild tracheal deviation to the right. No invasion of the surrounding structures. Further, smaller nodules are also seen in the right thyroid lobe.
There is no lymphadenopathy.
The tongue and the floor of the mouth have a normal appearance.
The pharyngeal and glottic regions are normal. The parapharyngeal fat space is normal. The tonsils and adenoids are normal.
The parotid and submandibular glands are unremarkable.
The imaged brain parenchyma is unremarkable. The orbits, paranasal sinuses and the mastoid air cells are clear.
Pleuro-parenchymal scarring is seen in both pulmonary apices.
No bony abnormality is seen.
Conclusion:
Enhancing left level IVa mass lesion adjacent to the left thyroid lobe with similar characteristics as the thyroid gland, suspicious of accessory thyroid gland. The differential diagnoses includes recurrent nerve schwannoma and nodal disease. Histological evaluation is advised.
Known multinodular goitre with enlarged left thyroid lobe.