Imaging of basal cell carcinoma by high-definition optical coherence tomography: histomorphological correlation. A pilot study

Background With the continued development of noninvasive therapies for basal cell carcinoma (BCC) such as photodynamic therapy and immune therapies, noninvasive diagnosis and monitoring become increasingly relevant. High-definition optical coherence tomography (HD-OCT) is a high-resolution imaging tool, with micrometre resolution in both transversal and axial directions, enabling visualization of individual cells up to a depth of around 570 mu m, and filling the imaging gap between conventional optical coherence tomography (OCT) and reflectance confocal microscopy (RCM). Objectives We sought to determine the feasibility of detecting BCC by this technique using criteria defined for RCM and conventional OCT and compared with histology. Methods In this pilot study skin lesions of 21 patients with a histologically proven BCC were imaged by HD-OCT just before excision and images analysed qualitatively. Results Features for four different BCC subtypes were described in both transverse and axial directions. In general, these features were subepidermal or intradermal aggregations of cells. These islands or trabeculae were surrounded by a less refractile border corresponding with palisading and peritumoral mucin production. There was a pronounced architectural disarray of the epidermis. A variably refractile stroma together with abundant dilated peritumoral blood vessels was present. These features were comparable with histological features for each patient. Conclusions Using features already suggested by RCM and conventional OCT, the study implies that HD-OCT facilitates in vivo diagnosis of BCC and allows the distinction between different BCC subtypes for increased clinical utility.