case_images: PMC6172832_01
case_images: Local findings on electron spectroscopy (right channel view). The tumor is indicated by the black arrow
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case_images: PMC6172832_01_12907_2018_76_Fig1_HTML.jpg
case_images: Fig1
case_images: A round tumor with a diameter of approximately 10 mm that involved the posterior end of the nasal septal mucosa at the midline of the epipharynx was discovered in a 58-year-old man while screening for laryngeal cancer (Fig. 1).
case_images: Tumor imaging. a Computed tomography image (no enhancement) and (b) magnetic resonance image (T1-weighted image gadolinium positive). White arrows show the tumor
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case_images: PMC6172832_01_12907_2018_76_Fig2_HTML.jpg
case_images: Fig2
case_images: Plain computed tomography (CT) revealed a soft tissue shadow tumor approximately 10 mm in size in the vault of the nasopharynx at the junction of the nasal septum and roof (Fig. 2a). T2-weighted images showed the same intensities as that of the nasal concha, and a regular contrast effect was observed (Fig. 2b). These MRIs suggested a benign tumor.
case_images: Hematoxylin-eosin staining of tumor samples. a Tubular formation, (b) papillary structure, and (c) solid growth of spindle cells. All magnifications are x 200
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case_images: PMC6172832_01_12907_2018_76_Fig3_HTML.jpg
case_images: Fig3
case_images: Hematoxylin-eosin staining showed that the tumor had a papillary structure lined by a columnar epithelium with a hyalinized fibrous core, and was additionally composed of sheets of spindle cells (Fig. 3); these two types of structures merged imperceptibly.
case_images: Immunohistochemical staining of tumor samples. The left side shows spindle cells while the right side shows columnar cells. The tumor was positive for (a) CK7 and (b) thyroid transcription factor-1, and was negative for (c) PAX8 and (d) p40. All magnifications are x 200
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case_images: Fig4
case_images: TTF-1 (Fig. 4b), CK19, and vimentin (data not shown); however, they were negative for CK20, p63, smooth muscle actin (SMA), S-100, Epstein-Barr-encoded RNA (EBER), p16, human papillomavirus (HPV), and thyroglobulin (data not shown). The Ki-67 index was approximately 2-3%.