title: Pigmented purpuric dermatosis: classification by phenotypic and molecular profiles.
abstract: The categorization of pigmented purpuric dermatosis (PPD) as a form of cutaneous lymphoid dyscrasia has been suggested. Phenotypic and molecular studies were done on 43 patients with PPD. The molecular studies used a capillary gel electrophoresis T-cell receptor beta multiplex polymerase chain reaction assay. There were 2 principal categories: polyclonal PPD represented by 22 cases and monoclonal variants comprising 21 cases. Monoclonal cases had extensive skin lesions. An identical restricted T-cell repertoire independent of time and location was observed. Approximately 40% of the monoclonal cases had clinical and pathologic features of mycosis fungoides (MF). In the polyclonal variant, disease outside the lower extremities was uncommon; there were no patients with MF. Striking reductions in CD7 and CD62L were seen in both groups. PPD is a form of cutaneous T-cell lymphoid dyscrasia, based on the frequency of monoclonality, the preservation of persistent T-cell clonotypes, and extent of pan-T-cell marker loss. Stratification of lesions of PPD according to the molecular profile may be of significant value prognostically and influence therapeutic intervention.
authors.affiliation: Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University New York Presbyterian Hospital-Cornell Campus, New York, NY 10021, USA.
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Magro
authors.forename: Jochen T
authors.initials: JT
authors.lastname: Schaefer
authors.forename: A Neil
authors.initials: AN
authors.lastname: Crowson
authors.forename: Jingwei
authors.initials: J
authors.lastname: Li
authors.forename: Carl
authors.initials: C
authors.lastname: Morrison
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019011:Antigens, CD7 / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D019041:L-Selectin / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010859:Pigmentation Disorders / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D011693:Purpura / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000473:pathology
chemical_list: D019011:Antigens, CD7; D019041:L-Selectin