Context: Immunohistochemistry has become an integral component of the practice of pathology. Newer antibodies allow for increasingly precise diagnoses for tumors that previously could not be easily identified. Recently, immunohistochemical evaluations have begun to allow pathologists to actively assist in determining prognosis and even in selecting therapies.
Objective: To summarize the usefulness of currently available immunostains for the study of liver and gastrointestinal system neoplasms and to make recommendations for panels of immunostains that can be particularly helpful.
Data sources: Information has been collected from recent literature as well as from personal experience and practice.
Conclusions: Many immunostains are now available for the practicing pathologist that allow for increasing accuracy in diagnosis of liver and gastrointestinal tract neoplasms. Panels of immunostains can be used to differentiate between various tumors and also to identify site of origin in the case of a metastatic neoplasm. Immunostains that allow for prognostic determinations and for guidance in the selection of chemotherapeutic agents can also be used by pathologists to assist in the management of patients with malignant tumors affecting the liver and gastrointestinal tract.