Diagnostic and Predictive Immunocytochemistry in Head and Neck Lesions.

Background: The application of immunocytochemistry (ICC) as a diagnostic and predictive tool in the workup of head and neck lesions has followed the changes and progresses in the surgical pathology evaluation. The contribution of ICC has shown a significant role in head and neck cytology, demonstrating as its contribution can support the diagnosis of many lesions. Furthermore, its role has been evolving as an important adjuvant tool in targeted therapies. An additional useful role is defined by the recent introduction of ICC markers related to genetic alterations, which has opened the door to the adoption of a surrogate for molecular evaluation also on cytological material.

Summary: The current review article analyzes the role of ICC in the field of head and neck cytology, showing that it might represent a valid diagnostic tool in difficult cases. The review will include all the different head and neck lesions, demonstrating how we could rely on organ-specific ICC markers but also on ICC markers able to discriminate between benign and malignant lesions.

Key Messages: The role of ICC represents a valid additional tool in the management of several difficult lesions, especially when morphology alone is not able to make a conclusive diagnosis. The support of ICC is likely to support the morphological findings leading to the definition of the diagnosis and the most appropriate management.