The patient has primary thyroid lymphoma, which most often occurs in elderly women with a long-standing history of Hashimoto thyroiditis. The clinical presentation is typically one of rapid onset (weeks) of an enlarging goiter with weight loss and night sweats. The diagnosis is made by biopsy of the thyroid with flow cytometry. Treatment typically involves chemotherapy and/or radiation therapy. Thyroidectomy is usually not needed.
CT scan of the neck, rather than ultrasound, was ordered in this patient because of the compressive symptoms and positional breathing issues. CT scan allows visualization of the enlarged thyroid gland and assessment of the patency of the trachea. In this image, the “doughnut” sign can be seen, whereby the enlarged thyroid extends behind and completely encircles the trachea.
New-onset Graves disease is unlikely to occur in a patient of this age, particularly with her long-standing history of hypothyroidism. Furthermore, there is no bruit or other clinical sign of Graves disease, and the thyromegaly associated with Graves disease is not acute in onset.
This patient is unlikely to have papillary thyroid cancer, as these tumors typically grow very slowly, in contrast to the acute onset of her findings. Additionally, the thyroid is not typically diffusely enlarged, as seen on this CT scan. Rather, a distinct nodule and potentially concomitant cervical lymphadenopathy would be expected.
Subacute (de Quervain) thyroiditis is associated with acute onset of anterior neck pain. It is typically seen following a viral illness in the preceding months. The changes on CT are typically a patchy infiltrate with minimal lymphadenopathy. This patient's image reveals marked diffuse enlargement of the thyroid, and she did not have a history of prior illness.
