Abstract
Although basal cell carcinoma is a well-known tumor with confirmed clinical and histopathology traits, prognosis factors and treatment options, new facets of this tumor emerge as innovative approach methods develop. Reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) allow a basal cell carcinoma's in vivo analysis of its depth of invasion, tumor margins prior to surgical approach and the tumor's response to a non-invasive treatment, evaluating simultaneously the tumor's vasculature. By RCM and OCT analysis, basal cell carcinoma has registered a groundbreaking discovery regarding a small (but with predictive factor potential) trait - the cleft, developing in between the tumor islands/nodules/chords and the surrounding tumor stroma; it was considered to date as a consequence of the tissue's histopathology processing. RCM and OCT revealed that the "clefting artifact", as it is frequently found in the medical literature, is not actually an artifact of laboratory processing, but a tumor trait found in vivo, with apparent mucin deposits. This review aims at merging the methods of evaluating basal cell carcinoma, both non-invasive (dermoscopy, RCM, OCT) and invasive ones (histopathology - with newly proposed classification), with special emphasis on the cleft issue - its assessment with the aforementioned techniques, with potential implications in the patient's prognosis.