title: Comparative histopathologic analysis of cutaneous extranodal natural killer/T-cell lymphomas according to their clinical morphology.
abstract: BACKGROUND
  Few studies have evaluated the histopathologic features of cutaneous extranodal natural killer (NK)/T-cell lymphoma (ENKTL), and the histopathologic spectrum of this disease according to its clinical morphology remains unclear.
  
  
  OBJECTIVE
  This study investigated the differences in pathologic findings of cutaneous ENKTL depending on clinical morphology.
  
  
  METHODS
  A total of 41 cases of cutaneous ENKTL were included. Skin lesions were classified according to clinical morphology as: (i) nodular lesions, (ii) cellulitis or abscess-like swellings and (iii) erythematous to purpuric patches. Histopathologic variables were compared between groups.
  
  
  RESULTS
  Perivascular infiltration of tumor cells and vasculopathy in the dermis and subcutaneous layer were common microscopic findings irrespective of clinical morphology. Erythematous to purpuric patches were mainly composed of small-sized tumor cells, whereas medium- to large-tumor cells were predominant in lesions of other clinical morphologies. The density of tumor cell infiltration was significantly higher in cellulitis or abscess-like lesions or nodular lesions compared with erythematous to purpuric patches. A panniculitis-like pattern and angiocentricity were less common in patch lesions than in cellulitis-like swelling and nodular lesions.
  
  
  CONCLUSIONS
  There is a histopathologic spectrum of cutaneous ENKTL that is dependent on the clinical morphology.
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Lee
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Mi Hye
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chong Hyun
authors.initials: CH
authors.lastname: Won
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sung Eun
authors.initials: SE
authors.lastname: Chang
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jee Ho
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Kee Chan
authors.initials: KC
authors.lastname: Moon
authors.affiliation: Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chan-Sik
authors.initials: CS
authors.lastname: Park
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Mi Woo
authors.initials: MW
authors.lastname: Lee
mesh_terms: D005260:Female; D006801:Humans; D016410:Lymphoma, T-Cell, Cutaneous / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D055611:Natural Killer T-Cells / Q000378:metabolism / Q000473:pathology; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology*
keywords: clinical morphology; histopathology; lymphoma; natural killer/T-cell lymphoma; skin