Blue nevus is a type of pigmented nevus, usually presenting as a solitary, well‑demarcated blue or black nodule. The blue hue results from pigment‑bearing cells located deep within the skin.
A biopsy may be performed, or the entire lesion may be surgically excised. The prognosis is generally favorable, with only a small risk of malignant transformation. Differential diagnoses include dermatofibroma and melanoma.
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.
Because the nevus cells are deeply present, it appears blue.
Atypical example — A blue nevus usually has a symmetrical shape. In such cases, basal cell carcinoma and melanoma should be differentiated.
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.
A biopsy may be performed, or the entire lesion may be surgically excised. The prognosis is generally favorable, with only a small risk of malignant transformation. Differential diagnoses include dermatofibroma and melanoma.