FIG 3. 32-year-old man with a recurrent episode of left-sided neck infection.

A, CT scan shows diffuse swelling and enhancement of the soft-tissue plane (arrows) around the left pyriform fossa.

B, Axial contrast-enhanced CT scan shows an abscess in the perithyroid tissue (arrows). Note the focus of air density in the perithyroid abscess (arrowhead).

C, Hypopharyngoscopic study reveals a sinus opening at the pyriform sinus apex (arrow) with a view from above and anterior toward the bottom. R indicates right; L, left; A, anterior; P, posterior.