PMC5688359_01
(a) Anterior view from initial 99mTc-pertechnetate thyroid scan. There is heterogeneous uptake in a lobulated mass (arrows) superior to the right lobe of the thyroid. Uptake in the thyroid gland is relatively homogeneous. There is normal physiologic uptake in the submandibular glands (SMG). 131Iodine scan (b) demonstrates intense radioiodine uptake in the mass.
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fig1
A 99mTc-pertechnetate thyroid scan was performed (Figure 1(a)) after discontinuing methimazole for 4 days, which revealed heterogeneous uptake in a large lobulated mass superior to the right lobe of the thyroid. An 131Iodine scan was then performed (Figure 1(b)) that revealed intense radioiodine uptake in the mass, confirming that it was indeed thyroidal in origin.
SPECT-CT images from the second 99mTc-pertechnetate thyroid scan ((a) axial, (b) coronal, and (c) sagittal) localize the mass to the posterior right hypopharynx.
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fig2
TSH to <0.01 mIU/L with fT4 being 16.1 pmol/. 99mTc-pertechnetate was repeated which was similar in appearance (not shown). This time SPECT-CT (Single Photon Emission Computed Tomography-Computed Tomography) imaging was also performed to better localize the mass, revealing it to be in the right posterior hypopharynx, measuring up to 4 cm cranial-caudal (Figure 2).
Photomicrograph of the edge of the dominant nodule, showing irregularly dilated follicles with pale colloid and subtle infoldings of the follicular epithelium. The follicular cells are uniform and evenly spaced, without features of papillary thyroid carcinoma (H&E, 100x).
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fig3
Focal papillary infoldings of hyperplastic follicular cells extended into the dilated follicles (Figure 3).