Dendritic cells in pigmented basal cell carcinoma: a relevant finding by reflectance-mode confocal microscopy.
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.
Segura
Sonia
S
Department of Dermatology, Hospital Clinic Barcelona, Villarroel 170, 08036 Barcelona, Spain.
Puig
Susana
S
Carrera
Cristina
C
Palou
Josep
J
Malvehy
Josep
J
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