ABSTRACT
Objective To investigate the clinicopathological features,immunophenotype,diagnosis and differential diagnosis of oncocytic mucoepidermoid carcinoma(OMEC).Methods A case of OMEC was studied for clinicopathological and immunohistochemical features,the available literature on this subject was reviewed as well.Results Magnetic resonance imaging revealed a well-defined mass,measured 1 cm×1 cm,within the right submandibular gland.The patient was underwent the total mass and the right submandibular gland resections.On macroscopic examination,the well-defined tumor was gray-yellowish on cut surface with hard consistence and was sized 1 cm×1 cm×0.8 cm.The uncapsulated tumor was mainly solid with focal microcysts on cut surface.Microscopically,the tumor consisted of nests,sheets,and occasional microcysts of oncocytic cells.Focally,intermediate cells,mucilage cell and epidermoid cell were also present.Immunohistochemically,the oncocytic cells were diffusely and intensely positive for CK(AE1/AE3),EMA and P63.By histochemical staining,the oncocytic cells were positive for PTAH staining,and mucilage cell were positive for PAS staining.Conclusion The OMEC is an exceedingly rare variant of mucoepidermoid carcinoma with a good prognosis and should be differentiated from oncocytoma,oncocytic carcinoma,Warthin's tumor with mucinous metaplasia,pleomorphic adenoma,oncocytic myoepithelioma and myoepithelial carcinoma,et al.
ABSTRACT
Oncocytic lipoadenoma is a rare tumor, with only 18 cases having been reported since the first in 1998. We encountered a case of oncocytic lipoadenoma presenting as a slowly growing parotid mass in a 71-year-old man. This tumor is characteristically comprised of a mixture of oncocytes and adipocytes. The present case is one of five reported cases of oncocytic lipoadenoma showing sebaceous differentiation. The results of immunohistochemical study with DOG1 antibody supported the origination of this tumor in the striated duct.