Multiple pigmented trichoblastomas, sebaceous carcinoma and syringocystadenoma papilliferum arising within a nevus sebaceous

We present a 43-year-old man with a 3-year history of slowly-enlarging pigmented nodules on his right face. The patient reported a yellowish verrucous plaque on the right side of his face since birth. At the age of 10 years, cryotherapy was applied to remove the plaque, leaving a residual scar-like patch. Three years ago, the patient noted several pigmented nodules within the patch. A new nodule appeared in another area of the patch one year ago and grew rapidly. The patient denied any personal or [...]