Mammaglobin immunoexpression in some malignant salivary gland neoplasms as a potential diagnostic tool for tumor ductal differentiation

IntroductionDespite being a rare daily histopathologic diagnosis, malignant salivary gland (SG) tumors show significant morphologic diversity that could obscure their diagnosis. Recognizing specific microscopic patterns together with the aid of ancillary techniques, such as immunohistochemistry, represent the clues to precise diagnosis. Mammaglobin (MMg) is a member of secretoglobin protein family that is widely associated with breast cancer and strongly expressed by secretory carcinoma of SGs. Its expression in other malignant SG neoplasms should be investigated.ObjectivesInvestigating the immunohistochemical expression of MMg in some malignant SG tumors to detect its potential diagnostic value.Material and MethodsNineteen paraffin-embedded, archival specimens of malignant SG tumors were divided into two groups according to presence or absence of ductal differentiation. Specimens were immunohistochemically stained using anti-MMg protein.ResultsMMg expression was more upregulated in the ductal differentiation group as compared to the other group of neoplasms.ConclusionMMg would represent a promising diagnostic tool in discriminating SG tumors with ductal and/or secretory activity.