title: Intralymphatic CD30+ T-cell proliferation during DRESS: a mimic of intravascular lymphoma.
abstract: BACKGROUND
  We describe the case of a patient presenting with drug rash with eosinophilia and systemic symptoms (DRESS), where cutaneous biopsy revealed intravascular atypical lymphocytes suggestive of lymphoma.
  
  
  METHODS
  A 77-year-old man was treated with antibiotics for a hip prosthesis infection. Eight weeks later, he developed a maculo-papulous eruption, edema of the extremities, fever and blood eosinophilia. Cutaneous biopsy revealed an atypical T-cell proliferation into the dermal lymphatic vessels. The lymphocytes were mid-sized, with mitoses and apoptotic figures. They were CD3+, CD4+, CD5+ and some were CD30+. There was no T-cell receptor (TcR) clonal rearrangement. Complete regression of cutaneous eruption and eosinophilia was observed after ceasing treatment with antibiotics. The diagnosis was that of a benign atypical intralymphatic T-cell proliferation associated with DRESS.
  
  
  CONCLUSIONS
  The occurrence of atypical dermal CD30+ T-cells in cutaneous biopsy during benign reactive conditions such as arthropod bites or scabies is well-known. The intralymphatic localization of such atypical reactive lymphocytes is much less common and represents a diagnostic pitfall because it can suggest aggressive intravascular lymphoma.
  
  
  CONCLUSIONS
  We report the first case of benign atypical intralymphatic CD30+ T-cell proliferation associated with DRESS. Diagnostic clues include immunohistochemistry, absence of TcR clonal rearrangement, and anatomo-clinical correlation.
authors.affiliation: Department of Pathology, Strasbourg University Hospital, Strasbourg, France. noelle.weingertner@chru-strasbourg.fr.
authors.forename: Noëlle
authors.initials: N
authors.lastname: Weingertner
authors.affiliation: Department of Dermatology, Strasbourg University Hospital, Strasbourg, France.
authors.forename: Mona
authors.initials: M
authors.lastname: Mitcov
authors.affiliation: Department of Pathology, Strasbourg University Hospital, Strasbourg, France.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Chenard
authors.affiliation: Department of Dermatology, Strasbourg University Hospital, Strasbourg, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Cribier
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D049109:Cell Proliferation; D003937:Diagnosis, Differential; D063926:Drug Hypersensitivity Syndrome / Q000276:immunology*; D006801:Humans; D017730:Ki-1 Antigen / Q000378:metabolism*; D008213:Lymphocyte Activation; D008297:Male; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology
chemical_list: D000900:Anti-Bacterial Agents; D017730:Ki-1 Antigen
keywords: CD30; DRESS; Drug-induced eruption; intralymphatic proliferation of T-cell lymphoid blasts; intravascular lymphoma