Which is not a tumour known to commonly arise from a sebaceous (organoid) naevus?A. Basal cell carcinoma (BCC)
Mycosis fungoides. This is not a tumour known to commonly arise from a sebaceous naevus. BCC is the most common malignant tumour, but benign tumours such as tricholemmoma, trichoblastoma and syringocystadenoma are much more common. Mycosis fungoides is a cutaneous T-cell lymphoma and is unrelated. Older series suggested malignant potential to be 10-15%, but more recent series suggest this rate is much lower. The tumours arise in adolescence or early adult life but can occur in children under 5 years.