Periostin Expression in Malignant Lymphoma and Warthin’s Tumor

Background: In the present study, we focused on the periostin expression in Warthin’s tumor and malignant lymphomas, which require differentiation from these tumors. Objectives: we investigated the expression and the roles of periostin in the formation of parotid gland mass. Methods: Twenty-eight samples of parotid gland mass were investigate histopathologically and immunohistochemically. Result: Pathologically, tumors were diagnosed as Warthin’s tumors in 15 specimens and malignant lymphomas in 13 specimens. Increased periostin expression was observed in the stroma of Warthin's tumor and malignant lymphoma in 24 of 28 samples (12 Warthin's tumor, 12 malignant lymphoma) (85.7%). Periostin expression was observed in three different patterns: negative, superficial, and infiltrative. Statistically significant differences were found between the histological classification of the tumors　and periostin expression patterns. When periostin expression was examined in the same 28 specimens, increased periostin expression was observed in the tumor capsule in 13 specimens (46.4%). A statistically significant association was found between the presence or absence of periostin expression within the tumor capsule and the histology of parotid tumors. Conclusion and significance: Periostin may be involved in the development of Warthin's tumor and malignant lymphoma. Periostin may serve as a new biomarker for these diseases.