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Updated: May 1, 2026

Automated Multiplex Immunofluorescence Panel for Immuno-oncology Studies on Formalin-fixed Carcinoma Tissue Specimens
Published on: January 21, 2019
Preliminary diagnostic criteria for distinguishing metaplastic Warthin tumors from mucoepidermoid carcinomas rich in
João Felipe Leite Bonfitto1, João Figueira Scarini2, Iara Vieira Ferreira2
1Pathology Department, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil.
Objective:
This study aimed to analyze the clinicopathological and immunohistochemical profiles of unconventional Warthin tumors and mucoepidermoid carcinomas.
Methods:
Eleven low-grade salivary gland tumors with Warthin-like features were analyzed. Group A (n=6) showed a double-layered oncocytic epithelium in less than 50% of the epithelial cells, whereas Group B (n=5) lacked this feature. Additionally, five conventional Warthin tumors and ten conventional mucoepidermoid carcinomas were analyzed as reference groups. Immunohistochemical staining was performed for cytokeratins (types 5/6, 7, and 14), p63, mitochondrial antigens, and Ki-67. Expression patterns were compared between groups.
Results:
Group A exhibited an oncocytic epithelium arranged in a double-layered pattern, with mitochondrial antigens strongly staining the luminal oncocytic cells. Cytokeratin 7 expression in Warthin tumors was predominantly luminal. In contrast, Group B showed glandular and cystic structures with diffuse mitochondrial antigen and cytokeratin 7 positivity. Immunohistochemical analysis revealed significant differences, with Warthin tumors showing distinct double-layered epithelial structures, and mucoepidermoid carcinomas displaying diffuse staining patterns.
Conclusion:
Distinct immunohistochemical profiles, including mitochondrial antigen and cytokeratin 7 expression, along with morphological differences, support the classification of Group A as metaplastic Warthin tumors and Group B as Warthin-like variants of mucoepidermoid carcinoma. These findings highlight the importance of molecular and immunohistochemical analyses for accurate classification of these tumors.

