Blue nevus is a type of melanocytic nevus. The blue colour is caused by the pigment being deeper in the skin than in ordinary nevi. In principle they are harmless but they can sometimes be mimicked by malignant lesions, i.e. some melanomas can look like a blue nevus.
Blue nevus 是指因黑色素細胞過度增生而形成的皮膚病變，常在頭部、手臂或臀部出現藍色至黑色的斑塊。它們大多為單發且後天獲得，但亦可能先天存在且分布於多個部位。此類病灶常被誤認為黑色素瘤等深色素腫瘤，常見於頭皮、手臂、下背部或臀部，呈藍色。 The term blue nevus describes a group of skin lesions characterized by dermal proliferation of melanocytes presenting as blue to black nodules on the head, extremities, or buttocks. In most cases, they are acquired and present as a solitary lesion but may also be congenital and appear at multiple sites. Blue nevi are melanotic dermal lesions that commonly presents as a blue nodule on the scalp, extremities, sacrococcygeal region, or buttocks. Its characteristic blue to black hue is frequently confused with other darker pigmented lesions, including malignant melanoma.
有時會進行活檢，或直接手術切除整個病變。臨床預後通常良好，惡性轉變的機會很低。鑑別診斷包括皮膚纖維瘤和黑色素瘤。