RT Book, Section A1 Dunphy, Cherie H. A1 Fedoriw, Yuri A1 Mathews, Stephanie P. A1 Perjar, Irina A2 Reisner, Howard M. SR Print(0) ID 1173780915 T1 Hematopathology T2 Pathology: A Modern Case Study, 2e YR 2020 FD 2020 PB McGraw-Hill Education PP New York, NY SN REISNERPATHOL LK accessmedicine.mhmedical.com/content.aspx?aid=1173780915 RD 2024/10/05 AB WHAT WE DOHematopathology is one of the most diverse areas of pathology, since it represents a hybrid discipline involving clinical pathology (i.e., laboratory medicine) and anatomic pathology (surgical pathology of lymph nodes and extranodal tissues involved by hematolymphoid disorders). This field of pathology also uses cytomorphology and histology in combination with numerous ancillary tools (i.e., enzyme cytochemical and immunohistochemical staining, flow cytometric immunophenotyping, and cytogenetic and molecular techniques) in diagnosing and prognosticating hematolymphoid disorders. In some instances, the appropriate diagnosis of the hematolymphoid disorder also relies heavily on clinical and radiologic data.For example, acute promyelocytic leukemia (APL) (as described later in this chapter) has characteristic cytomorphological, enzyme cytochemical, and flow cytometric immunophenotypic features that are defined by the ever-present t(15;17)(q24;21) or similar chromosomal variant. This translocation may be detected most rapidly by fluorescence in situ hybridization (FISH) performed in the cytogenetics laboratory. It is important to recognize this subtype of acute myeloid leukemia (AML) as soon as possible, since it is often associated with disseminated intravascular coagulation (DIC) and has a specific therapy (different from all other forms of AML).As an additional example, evaluation of plasma cell proliferations relies heavily on cytomorphological and histological features in combination with immunohistochemical and in situ hybridization studies for clonality. However, even with these techniques, the appropriate classification (and prognostication) of the plasma cell neoplasm (PCN) must be based on close integration of the clinical, radiologic, and cytogenetic data in each case, as described again later in this chapter.