Reflectance confocal microscopy of pigmented basal cell carcinoma

BackgroundReflectance confocal microscopy (RCM) is a high-resolution imaging tool for in vivo noninvasive evaluation of skin lesions.ObjectiveWe sought to describe the relevant RCM features for pigmented basal cell carcinoma (BCC).MethodsPigmented skin lesions with a differential diagnosis of pigmented BCC were imaged using dermoscopy and RCM, followed by excision for histologic analysis.ResultsRCM demonstrated aggregations of tightly packed cells with palisading, forming cordlike structures and nodules with irregular borders and variable brightness; these represented nests of pigmented basaloid tumor cells on histopathology, and blue-gray ovoid areas on dermoscopy. These tumor nests were associated with bright dendritic structures, identified histologically as either melanocytes or Langerhans cells, together with numerous bright oval to stellate-shaped structures with indistinct borders representing melanophages, and with highly refractile granules of melanin.LimitationsThe pigmented BCCs imaged in this study were predominantly nodular; a different set or additional criteria may be necessary for detection of infiltrative and metatypical BCCs.ConclusionRCM may permit in vivo diagnosis of pigmented BCC.