Topics in Hematopoietic Neoplasms: Controversies in Diagnosis and Classification include: ABC vs GC subtyping of diffuse large B cell lymphoma-Does it matter?; Clonal link between malignant lymphoma and histiocytic tumors; Diagnostic criteria for grey zone lymphoma: Are there any?; Diagnostic criteria for primary cutaneous B cell lymphoma; Distinguishing reactive and leukemic large granular lymphocyte proliferations; Differential diagnosis of erythroleukemia; Early pre-T ALL versus MPAL: Diagnostic criteria; Myeloid neoplasms with inv(3) or t(3;3); Update on classification and prognosis in...