Definition of Disease and Nomenclature Hairy cell leukemia (HCL) is a mature B-cell neoplasm that involves primarily the blood, bone marrow, and splenic red pulp. The neoplastic lymphocytes have surface “hairy” projections and express the B-cell–associated antigens CD19, CD20, and…
Definition of Disease Lymphoplasmacytic lymphoma (LPL) is defined in the WHO Classification of Tumours of Haematopoetic and Lymphoid Tissues, fourth edition, as a small B-cell neoplasm composed of lymphocytes, plasma cells, and plasmacytoid lymphocytes, which does not meet criteria for…
B-Cell Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (B-CLL/SLL) Definition of Disease B-cell chronic lymphocytic leukemia (B-CLL) is a clonal disorder of mature B lymphocytes, which are characterized by small, round nuclei; highly condensed chromatin; inconspicuous nucleoli; scant cytoplasm; and unique immunophenotype.…
Historical Background The classification of lymphoid neoplasms used in this text is the one published by the World Health Organization (WHO) in WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues . Initially published in 2008, the WHO's fourth edition…
This chapter addresses the peripheral blood and bone marrow response to a variety of non-malignant conditions. A bone marrow examination may be performed to evaluate a fever of unknown origin, looking for a specific infectious cause. In inflammatory or metabolic…
Quantitative and qualitative abnormalities of the peripheral blood are routinely detected with an automated complete blood count (CBC) and examination of a peripheral blood smear. The peripheral blood evaluation serves as a screening test for potential bone marrow abnormalities and…
Although hematopoietic stem cells circulate in small numbers, hematopoiesis, in steady-state conditions in adult life, is largely confined to the bone marrow. All lymphopoietic and hematopoietic cells are ultimately derived from pluripotent hematopoietic stem cells—slowly cycling cells with a capacity…
The major question that confronts the surgical pathologist when examining a lymph node biopsy is whether the process is benign or malignant. The pathologist must be familiar with the histologic changes of a diverse group of non-neoplastic disorders to differentiate…
Lymphoid tissues are the sites where precursor cells mature into immunocompetent lymphoid cells and where immune reactions to antigens occur. The lymphoid tissues and the stages of lymphocyte differentiation and maturation have an anatomy—they occur at specific sites in the…
Types of Chromosomal Aberrations in Hematologic Malignancies Introduction to Human Chromosomes In 1888, Waldeyer was first to introduce the term chromosome (meaning “stainable body,” from the Greek chroma, meaning “color,” and soma, meaning “body”). Waldeyer referred to Walther Flemming, who…