PMC2823682_01
Macroscopic and microscopic findings of the lesion. A: Endonasal view of the nasopharynx, with multiple melanotic lesions around the Eustachian tuber (left side). B: Microscopic findings of the lesion (hematoxylin and eosin stain, low magnification). C: Microscopic findings of the lesion (hematoxylin and eosin stain, high magnification). Plump epithelial cells with eosinophilic cytoplasm and many brown pigmented granules are arranged in a tubular pattern. D: Immunohistochemical findings of the lesion (S-100). S100-positive HMB45-negative dendritic cells were scattered in the lesion (arrows). By counterstaining with Giemsa stain, melanin pigment showed heterochromasia (green).
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F1
During nasoscopic examination multiple black nodules, measuring several millimeters, were discovered around the bilateral torus tubarius (Fig 1AB). These oncocytic cells had uniformly abundant eosinophilic granular cytoplasm on hematoxylin and eosin staining, and were arranged in a tubular or glandular pattern (Fig. 1C). Scattered brown pigments were also noted in the cytoplasm of oncocytic cells (Fig. 1C). By immunohistochemistry, S100-positive HMB45-negative dendritic cells were scattered in the lesion (Fig. 1D, arrows).