Trichoblastoma: is a clinical or dermoscopic diagnosis possible?

BackgroundTrichoblastoma is a rare benign skin tumour that must be differentiated from basal cell carcinoma for its benign course and favourable outcome. ObjectivesTo describe clinical and dermoscopic features of solitary primitive trichoblastoma and to compare them with trichoblastic basal cell carcinoma (tBCC). MethodsDigital dermoscopic images of 19 trichoblastoma and 19 tBCC were compared and reviewed by a dermatologist experienced in dermoscopy. ResultsThe most striking dermoscopic difference between trichoblastoma and tBCC was the presence of blue-grey globules and blue-grey ovoid nests that were found to be more frequent but not exclusive of tBCC. Arborizing vessels were found both in trichoblastoma and tBCC, with a lower frequency in the latter. ConclusionHistology remains the gold standard to differentiate trichoblastoma from tBCC.