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FIG 1. Case 1.
A, Axial, unenhanced CT scan through the inferior turbinate shows a large, homogeneous soft-tissue mass in the right nasal fossa.
B, Bone-window image (same level as A) shows aggressive destruction of the nasal septum and intersinonasal wall.
C, Coronal T1-weighted imaging with parameters 500/14/4 (TR/TE/excitations) shows the large tumor of intermediate signal intensity with extension into the skull base. Note the retention of mucosal secretion within the right maxillary sinus, of discrete higher signal intensity (arrowhead).
D and E, Dynamic T1-weighted imaging with parameters 500/14/4 (TR/TE/excitations) shows early enhancement (D) of the tumor 37 seconds after contrast medium administration (white arrow). Note that the mucosa overlying the inferior turbinate is not yet enhanced. At 75 seconds after contrast medium administration (E), the tumor is more enhanced. Notice the linear enhancement of the dura mater (arrowhead).
F, Immunostaining for keratin. Positivity has a distinct perinuclear dot-like quality, a characteristic feature of Merkel-cell carcinoma.
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