Maria Luisa C. Policarpio-Nicolas, MD
Department of Pathology, Spectrum Health Hospital, Blodgett Campus, Grand Rapids, Michigan

Mark R. Wick, MD
University of Virginia Medical Center, Department of Surgical Pathology and Cytopathology, Charlottesville, Virginia

Upon completion of this activity, you will be able to:

• enumerate the cytologic mimics of adenocarcinoma and squamous cell carcinoma.
• list the cytologic features that are useful in differentiating adenocarcinoma from reactive processes.
• list the cytologic features that are useful in differentiating squamous cell carcinoma from reactive processes.
• list a panel of immunohistochemical stains that are helpful in differentiating adenocarcinoma from a mesothelial proliferation.
• discuss potential solutions to the problem of false-positive diagnosis in respiratory cytopathology.