title: Verrucous carcinoma of the axilla: case report and review.
abstract: BACKGROUND
  Verrucous carcinoma, a variant of squamous cell carcinoma, is distinct from squamous cell carcinoma in morphology and behavior. It preferentially occurs on the oropharyngeal mucosa, the urogenital mucosa, and the soles. In contrast to its malignant clinical picture, the tumor grows locally invasive but is histologically benign and metastasizes rarely.
  
  
  METHODS
  We report the uncommon occurrence of a large verrucous carcinoma on apparently uninvolved skin in the right axilla in a 47-year-old male.
  
  
  RESULTS
  Histologic examination reveals a cauliflower-like tumor consisting of deep invaginated epidermal proliferation with rabbit burrow-like, keratin-filled sinus formations; the basement membrane, however, remains intact. Immunohistology showed positivity for pancytokeratin (KL-1) and cytokeratin (CK) 18 and negativity for CK7, and assessment of the proliferative activity of the tumor cells revealed low percentage of Ki-67 expression. Furthermore, there were only scattered cells expressing p53 or bcl-2. Polymerase chain reaction excluded the presence of human papillomavirus. After complete excision, no signs of recurrence occurred over a follow-up period of three years.
  
  
  CONCLUSIONS
  Verrucous carcinoma should be distinguished from typical squamous cell carcinoma. The clinicopathological features, differential diagnosis, and therapy are discussed here together with the molecular biologic aspects of the tumor.
authors.affiliation: Department of Dermatology, University Medical Center Benjamin Franklin, The Free University of Berlin, Berlin, Germany. chalid.assaf@medizin.fu-berlin.de
authors.forename: Chalid
authors.initials: C
authors.lastname: Assaf
authors.forename: Matthias
authors.initials: M
authors.lastname: Steinhoff
authors.forename: Ivailo
authors.initials: I
authors.lastname: Petrov
authors.forename: Christoph C
authors.initials: CC
authors.lastname: Geilen
authors.forename: Ethel-Michele
authors.initials: EM
authors.lastname: de Villiers
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schultz-Ehrenburg
authors.forename: Constantin E
authors.initials: CE
authors.lastname: Orfanos
mesh_terms: D001365:Axilla; D014408:Biomarkers, Tumor / Q000032:analysis; D018289:Carcinoma, Verrucous / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor