title: [Plasmacytic skin infiltration in multiple myeloma].
abstract: Authors present a case of a therapy-resistant multiple myeloma who developed plasmacytic skin infiltration in the course of the disease.
  
  
  OBJECTIVE
  To define characteristics of skin infiltrating plasma cells, which differentiate them from those cells residing in the bone marrow in order to contribute to a better understanding of the epidermoinvasion process.
  
  
  METHODS
  Histidine decarboxylase is the only enzyme capable for histamine synthesis having significance in cell proliferation. Histidine decarboxylase was determined in skin samples and bone marrow slides by immunohistochemical procedures and in bone marrow cells using flow cytometry analysis.
  
  
  RESULTS
  The histidine decarboxylase expression of plasma cells participating in skin invasion disappeared, while that of bone marrow plasma cells remained.
  
  
  CONCLUSIONS
  Authors conclude that the histidine decarboxylase loss would serve as an evidence for the dedifferentiation of epidermoinvasive cells as being the result of fundamental changes in histamine metabolism. As extramedullary myeloma cells differ from those residing in the bone marrow, their therapeutical response might also be different.
authors.affiliation: Semmelweis Egyetem, Altalános Orvostudományi Kar III, Belgyógyászati Klinika Budapest, Kútvölgyi út 4. 1125.
authors.forename: Katalin
authors.initials: K
authors.lastname: Molnár
authors.forename: István
authors.initials: I
authors.lastname: Karádi
authors.forename: István
authors.initials: I
authors.lastname: Sugár
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Sápi
authors.forename: Márta
authors.initials: M
authors.lastname: Marschalkó
authors.forename: Eva
authors.initials: E
authors.lastname: Pálinger
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Darvas
authors.forename: Péter
authors.initials: P
authors.lastname: Pócza
authors.forename: András
authors.initials: A
authors.lastname: Falus
authors.forename: András
authors.initials: A
authors.lastname: Vereczkei
authors.forename: Judit
authors.initials: J
authors.lastname: Várkonyi
mesh_terms: D000368:Aged; D001853:Bone Marrow / Q000201:enzymology; D005260:Female; D005434:Flow Cytometry; D006640:Histidine Decarboxylase / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D009101:Multiple Myeloma / Q000150:complications* / Q000473:pathology; D010950:Plasma Cells; D012867:Skin / Q000201:enzymology / Q000473:pathology*; D012871:Skin Diseases / Q000209:etiology* / Q000473:pathology
chemical_list: D006640:Histidine Decarboxylase