Avoiding pitfalls in diagnostic immunohistochemistry-important technical aspects that every pathologist should know.

This review focuses on technical aspects of diagnostic immunohistochemistry (IHC), with an emphasis on aspects of methodology and interpretation that may be problematic for practicing pathologists. Pitfalls in IHC are reviewed, and the importance of good controls and the the use of multi-tissue controls is discussed. Also covered is the optimal use of IHC in cytologic specimens and specimens where no paraffin block is available. Artifacts encountered in IHC are discussed and illustrated, and a number of useful techniques are described in detail, including preparation of multi-tissue control material, tissue and cell transfer techniques, and tissue protection techniques.