Figure 6

Recurrent nasopharyngeal carcinoma (NPC) in the mastoid antrum. The imaging follow up with computed tomography (CT) demonstrated a soft tissue mass (arrow in a: CT scan) in the right mastoid antrum of patient 26, who had been diagnosed and treated for NPC 2 years before. Magnetic resonance (MR) imaging showed an enhanced lesion in the right mastoid antrum (arrow in b and c: contrast-enhanced MR). Histological examination after biopsy revealed an undifferentiated non-keratinizing carcinoma, consistent with NPC (d: strong cytoplasmic staining of CK in tumor cells, ×100; arrows in e: positive Epstein-Barr virus-encoded RNA in situ hybridization (EBERs ISH) in tumor cell nuclei, ×100).