title: Large cell transformation of Sézary syndrome. A conventional and molecular cytogenetic study.
abstract: Hyperdiploidy sometimes is found in mycosis fungoides-Sézary syndrome, but its diagnostic significance remains undefined. We report an unusual case of Sézary syndrome manifesting with leukemic large cell transformation. Conventional karyotypic analysis showed the presence of a near-tetraploid neoplastic clone. With dual-color cytometric analysis, we showed that the large Sézary cells were near-tetraploid with a DNA index of 1.86, thereby demonstrating a direct relationship between cell size and ploidy. Comparative genomic hybridization further showed chromosomal imbalances that were not revealed on conventional karyotyping. Our findings suggest that hyperdiploidy may be a marker of large cell transformation, so that when this karyotypic abnormality is found in mycosis fungoides-Sézary syndrome, a search for such a complication is indicated.
authors.affiliation: Department of Pathology, Queen Elizabeth Hospital, Hong Kong, China.
authors.forename: C C
authors.initials: CC
authors.lastname: So
authors.forename: K F
authors.initials: KF
authors.lastname: Wong
authors.forename: L L
authors.initials: LL
authors.lastname: Siu
authors.forename: Y L
authors.initials: YL
authors.lastname: Kwong
mesh_terms: D000368:Aged; D002467:Cell Nucleus / Q000648:ultrastructure; D002471:Cell Transformation, Neoplastic; D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D005434:Flow Cytometry; D006801:Humans; D007621:Karyotyping; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics / Q000473:pathology*; D008297:Male; D009182:Mycosis Fungoides / Q000235:genetics / Q000473:pathology*; D009378:Neoplasms, Multiple Primary / Q000235:genetics / Q000473:pathology*; D009693:Nucleic Acid Hybridization; D011003:Ploidies; D012751:Sezary Syndrome / Q000235:genetics / Q000473:pathology*; D012878:Skin Neoplasms / Q000235:genetics / Q000473:pathology*