Atlas of Hematologic Neoplasms

Due to its rapid development in recent years, hematopathology has become a very complicated discipline. The current development is mainly in two aspects: the new classification of lymphomas and leukemias and the new techniques.

The Revised European-American Classification of Lymphoid Neoplasms (REAL classification) and the World Health Organization (WHO) classification of hematologic neoplasms require not only morphologic criteria but also immunophenotyping and molecular genetics for the diagnosis of hematologic tumors. Immunophenotyping is performed by either flow cytometry or immunohistochemistry. There are many new monoclonal antibodies and new equipments accumulated in recent years that make immunophenotyping more or more accurate and helpful. There are even more new techniques invented in recent years in the field of molecular genetics. In cytogenetics, the conventional karyotype is supplemented and partly replaced by the fluorescence in situ hybridization (FISH) technique. The current development of gene expression profiling is even more powerful in terms of subtyping the hematologic tumors, which may help guiding the treatment and predict the prognosis. In molecular biology, the tedious Southern blotting technique is largely replaced by polymerase chain reaction (PCR). The recent development in reverse-transcriptase PCR and quantitative PCR makes these techniques even more versatile.

Because of these new developments, hematopathology has become too complicated to handle by a general pathologist. Many hospitals have to hire a newly trained hematopathologist to oversee peripheral blood, bone marrow and lymph node examinations. These young hematopathologists are geared to the new techniques, but most of them are inexperienced in morphology. No matter how well-trained a hematopathologist is, he or she still needs to see enough cases so that they can recognize the morphology and use the new techniques to substantiate the diagnosis. In other words,