Acute myeloid leukemia (AML) is a heterogeneous group of diseases representing clonal proliferations of immature, nonlymphoid, bone marrow–derived cells that most often involve the bone marrow and peripheral blood and may present in extramedullary tissues. If untreated, AML follows an…
The myelodysplastic syndromes (MDS) are a set of diseases characterized by progressive peripheral cytopenias and dysplastic morphology of hematopoietic cells. MDS affects predominantly the elderly, but it can occur throughout life, including in childhood. MDS is a clonal hematopoietic neoplasm…
The 2016 revision of the fourth edition of the World Health Organization (WHO) classification of myeloid neoplasms, WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues , is used in this book. The principles of the WHO classification have been…
Standard classification criteria for acute leukemia derive from the morphologic, cytochemical, and immunophenotypic characterization of bone marrow specimens and are designed to identify optimal therapy and predict prognosis. On the basis of these criteria, most cases of acute leukemia can…
Classification of Precursor Lymphoid Neoplasms Precursor lymphoid neoplasms encompass acute lymphoblastic leukemias (ALLs) and lymphoblastic lymphomas (LBLs), generally of either B-cell or T-cell origin. The majority of ALLs are derived from precursor B cells, and the majority of LBLs possess…
Cutaneous T-cell lymphomas (CTCLs) comprise, for the most part, mycosis fungoides (MF) and variants and cutaneous CD30 + lymphoproliferative disorders, but other rare subtypes may be the source of diagnostic and therapeutic challenges. Some of these rare lymphomas show overlapping…
Definition Three types of primary cutaneous CD30 + lymphoproliferative disorders (LPDs) are recognized in the World Health Organization classification: primary cutaneous anaplastic large cell lymphoma (C-ALCL), lymphomatoid papulosis (LyP), and borderline lesions. These entities represent a continuous spectrum of lesions…
Mycosis fungoides and Sézary syndrome are two closely related conditions in which neoplastic T cells infiltrate the skin and circulate in the peripheral blood. Both conditions are neoplasms that typically have a mature helper T-cell phenotype and a propensity to…
Enteropathy-Associated T-Cell Lymphoma (Type I, Classical) An association between malabsorption and intestinal lymphoma was first reported in 1937, at which time lymphoma was considered responsible for the malabsorption. However, in 1962, Gough and coworkers demonstrated that intestinal lymphoma was a…
Definition and Background Among the heterogeneous group of hematopoietic neoplasms with a predominant population of large cells, Stein and colleagues recognized a subgroup of tumors with large cells exhibiting bizarre morphologic features and prominent sinusoidal invasion and expressing the Ki-1…