title: Primary cutaneous anaplastic large cell lymphomas with 6p25.3 rearrangement exhibit particular histological features.
abstract: OBJECTIVE
  CD30-positive primary cutaneous lymphoproliferative disorders include several entities with differing clinical presentation but overlapping histological features, including lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma (C-ALCL). DUSP22-IRF4 locus translocation is present in 20-57% of C-ALCLs, and has also been described in a series of 11 lymphomatoid papulosis patients, where it was associated with a particular biphasic histological pattern, including pagetoid reticulosis-type epidermal infiltration. We aimed to study whether the presence of this translocation may define distinctive histological features in C-ALCL.
  
  
  RESULTS
  We collected three cases of C-ALCL with histological features similar to those described in the new variant of lymphomatoid papulosis with 6p25.3 rearrangement. We studied their histological features and immunophenotype, using a panel of antibodies against CD30, TCR-βF1, TCR-γ, CD4, CD8, CD20, Ki-67 and ALK. FISH analyses were performed using an IRF4-DUSP22 break-apart probe for the study of the 6p25.3 rearrangement. FISH results were positive in the three cases, which all showed distinctive histological and immunohistochemical features: a diffuse dermal infiltrate of atypical medium-to-large cells, and marked epidermotrophism with small, atypical intra-epidermal lymphocytes.
  
  
  CONCLUSIONS
  Our findings suggest that the presence of 6p25.3 rearrangement might be related to this particular biphasic pattern.
authors.affiliation: Pathology Department, Hospital Universitario Marqués de Valdecilla, Santander, Spain.
authors.forename: Arantza
authors.initials: A
authors.lastname: Onaindia
authors.forename: Santiago
authors.initials: S
authors.lastname: Montes-Moreno
authors.forename: Socorro M
authors.initials: SM
authors.lastname: Rodríguez-Pinilla
authors.forename: Ana
authors.initials: A
authors.lastname: Batlle
authors.forename: Sonia
authors.initials: S
authors.lastname: González de Villambrosía
authors.forename: Antonio M
authors.initials: AM
authors.lastname: Rodríguez
authors.forename: Víctor
authors.initials: V
authors.lastname: Alegre
authors.forename: Glenda M
authors.initials: GM
authors.lastname: Bermúdez
authors.forename: Carmen
authors.initials: C
authors.lastname: González-Vela
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Piris
mesh_terms: D000368:Aged; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D054446:Lymphoma, Primary Cutaneous Anaplastic Large Cell / Q000235:genetics* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology*
keywords: 6p25.3 rearrangement; DUSP22-IRF4 translocation; biphasic pattern; lymphomatoid papulosis (LyP); primary cutaneous anaplastic large cell lymphoma (C-ALCL)