title: Dendritic cells in pigmented basal cell carcinoma: a relevant finding by reflectance-mode confocal microscopy.
abstract: BACKGROUND
  Reflectance-mode confocal microscopy (RCM) is a new approach for the in vivo diagnosis of skin tumors. A few studies of RCM on basal cell carcinoma (BCC) have provided specific diagnostic criteria, but large studies on pigmented basal cell carcinoma are lacking. Proliferation of large dendritic-shaped cells within a melanocytic tumor has been associated with the diagnosis of melanoma by RCM. Benign melanocytes and Langerhans cells may populate BCC according to previous histological studies. We studied 3 consecutive pigmented BCC by means of RCM and performed a histological and immunohistochemical correlation focusing on the presence of dendritic structures.
  
  
  METHODS
  Reflectance-mode confocal microscopy revealed highly refractive dendritic structures within tumor nests that correlated with the presence of melanocytes within the tumor by immunochemical analysis. In 1 case, dendritic structures on the overlying epidermis corresponding to Langerhans cells were also noted. Leaf-like areas observed on dermoscopy correlated with low-refractive cordlike structures and nodules by RCM and corresponded to nests of basaloid cells, whereas blue-gray globules presented as bright oval structures with ill-defined borders corresponding to melanophages.
  
  
  CONCLUSIONS
  Reflectance-mode confocal microscopy allows the study of pigmented BCC and the identification of specific criteria described previously. In these tumors, dendritic melanocytes can be easily identified with this technique.
authors.affiliation: Department of Dermatology, Hospital Clinic Barcelona, Villarroel 170, 08036 Barcelona, Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Segura
authors.forename: Susana
authors.initials: S
authors.lastname: Puig
authors.forename: Cristina
authors.initials: C
authors.lastname: Carrera
authors.forename: Josep
authors.initials: J
authors.lastname: Palou
authors.forename: Josep
authors.initials: J
authors.lastname: Malvehy
mesh_terms: D000368:Aged; D002280:Basal Cell Carcinoma / Q000175:diagnosis* / Q000473:pathology; D003713:Dendritic Cells / Q000166:cytology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008545:Melanoma / Q000175:diagnosis / Q000473:pathology; D018613:Microscopy, Confocal; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology