title: Lacking CD56 expression in a relapsing cutaneous blastic plasmacytoid dendritic cell neoplasm after allogeneic bone marrow transplantation: FISH analysis revealed loss of 11q.
abstract: BACKGROUND
  Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare entity characterized by a CD4+/CD56+/CD123+ immunophenotype and a fatal clinical course. The average survival of 12-14 months may be prolonged by allogeneic bone marrow transplantation (BMT).
  
  
  OBJECTIVE
  We report about a male patient who suffered from BPDCN with a typical histology and co-expression of CD4/CD123 and a CD56 expression by 80% of the tumour cells. The cutaneous tumour relapse after chemotherapy and allogeneic BMT was completely negative for CD56.
  
  
  METHODS
  We performed interphase fluorescence in situ hybridization (FISH) analysis of tumour tissue, asserved before and after BMT, using specific probes for chromosome 11, which encompass the CD56 gene region.
  
  
  RESULTS
  The tumour cells revealed a partial loss of 11q as well as a monosomy of chromosome 11.
  
  
  CONCLUSIONS
  This case demonstrates for the first time that loss of CD56 expression can also occur as a secondary event after chemotherapy and BMT. In our case, DNA loss of 11q23 could be responsible for the negativity of 20% of tumour cells as observed before chemotherapy. However, the complete loss of CD56 expression in the relapsed tumour cannot be explained by the loss of 11q23 alone. Additional factors such as chemotherapy-induced mutations might also have contributed.
authors.affiliation: Department of Dermatology, Georg August University Göttingen, Germany. christina.mitteldorf@klinikum-hildesheim.de
authors.forename: C
authors.initials: C
authors.lastname: Mitteldorf
authors.forename: H P
authors.initials: HP
authors.lastname: Bertsch
authors.forename: M
authors.initials: M
authors.lastname: Baumgart
authors.forename: D
authors.initials: D
authors.lastname: Haase
authors.forename: G
authors.initials: G
authors.lastname: Wulf
authors.forename: M P
authors.initials: MP
authors.lastname: Schön
authors.forename: A
authors.initials: A
authors.lastname: Rosenwald
authors.forename: C
authors.initials: C
authors.lastname: Neumann
authors.forename: K M
authors.initials: KM
authors.lastname: Kaune
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D016026:Bone Marrow Transplantation; D019002:CD56 Antigen / Q000235:genetics / Q000378:metabolism*; D002880:Chromosomes, Human, Pair 11 / Q000187:drug effects / Q000235:genetics*; D003520:Cyclophosphamide / Q000008:administration & dosage; D003713:Dendritic Cells / Q000473:pathology*; D004317:Doxorubicin / Q000008:administration & dosage; D005047:Etoposide / Q000008:administration & dosage; D017809:Fatal Outcome; D019337:Hematologic Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy*; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D011239:Prednisolone / Q000008:administration & dosage; D012867:Skin / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy*; D014184:Transplantation, Homologous; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D019002:CD56 Antigen; D014750:Vincristine; D005047:Etoposide; D004317:Doxorubicin; D003520:Cyclophosphamide; D011239:Prednisolone