title: [Ki-1 lymphoma].
abstract: ALCL is widely recognized with its broad morphologic and phenotypic spectrum causing controversy in the diagnosis of this peculiar neoplasm. It is now beyond doubt that a significant proportion(64 to 84%) of the cases diagnosed as ALCL is closely associated with the expression of chimeric NPM-ALK protein activated by the (2;5) (p23;q35) chromosomal translocation, which can be detected by anti-p80NPM/ALK or ALK1 antibodies. Recently, some investigators including us asserted that these p80NPM/ALK or ALK1-positive(p80/ALK+) ALCLs represent a distinct genetic entity with occurrence in young patients and a favorable prognosis, and should be differentiated from the p80/ALK- tumors with the relatively aggressive clinical course. The p80/ALK+ lymphomas also revealed the characteristic morphology such as horseshoe-like, kidney-like or doughnut-like nuclei and frequent expression of EMA and cytotoxic molecules. However, these features are shared, though to a lesser degree, by other p80/ALK-negative lymphoid neoplasms. Indeed, it is indicated that cytotoxic ALCL cases may be either p80/ALK positive or negative, suggesting that the cytotoxicity and expression of p80/ALK are independent phenomena among the cases of ALCL of T- and null-cell type. Thus, several areas of disagreement and controversy that surround the diagnosis and categorization of ALCL remain.
authors.affiliation: Department of Pathology and Genetics, Aichi Cancer Center.
authors.forename: S
authors.initials: S
authors.lastname: Nakamura
authors.forename: K
authors.initials: K
authors.lastname: Ichimura
authors.forename: K
authors.initials: K
authors.lastname: Sasaki
authors.forename: R
authors.initials: R
authors.lastname: Suzuki
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D002889:Chromosomes, Human, Pair 2; D006801:Humans; D017728:Lymphoma, Large-Cell, Anaplastic / Q000235:genetics / Q000473:pathology; D018396:Mucin-1 / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014178:Translocation, Genetic
chemical_list: D014408:Biomarkers, Tumor; D018396:Mucin-1; D011993:Recombinant Fusion Proteins