Figure 1

Histological features and immunohistochemical staining of both cases. A-B: Case 1, the tumor was demarcated from the surrounding slightly lipomatous parotid glands with a relative boundary. C-D: Case 1, within the tumor, solid and micropapillary pattern were observed. E-F: Case 2, the tumor was demarcated from the surrounding parotid glands with a clear boundary. G: Case 2, the tumor cells were uniform without significant cytologic and nuclear atypia. They displayed round to oval nuclei with fine chromatin and pale to amphophilic cytoplasm. H: Case 2, Apocrine differentiation of tumor cells was observed focally. I: The luminal tumor cells showed diffusive expression of S100 (Case 1 and 2). J: Immunostaining for p63 displayed a continuous rim of myoepithelial cells around all tumor islets (Case 1 and 2).