Blue_nevus_of_Jadassohn–Tièche
Blue nevus
Type of melanocytic tumor
A blue nevus is a type of coloured mole, typically a single well-defined blue-black bump.[1][2]
The blue colour is caused by the pigment being deep in the skin.[4]
Diagnosis is by visualisation and dermoscopy.[4] A biopsy is sometimes performed, or the whole lesion surgically removed.[3] The outcome is generally good but there is a small chance of cancerous transformation.[3] Differential diagnosis includes dermatofibroma and melanoma.[3]
Blue nevi are more common in females than males.[2] It was first studied in 1906 by Tièche, a student of Josef Jadassohn.[6]