Locally invasive cellular blue nevus of the scalp.
The cellular blue nevus, although benign by accepted pathological criteria, may behave in an aggressive fashion. Distant metastases may occur as malignant melanoma. This case illustrates the potential malignant degeneration and spread of a "benign" neoplasm. A broader definition of malignancy to include the clinical behavior of cellular blue nevus may be in order.
D000293:Adolescent; D006801:Humans; D008297:Male; D009508:Nevus, Pigmented / Q000473:pathology*; D009777:Occipital Bone / Q000473:pathology; D012535:Scalp / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*; D012888:Skull Neoplasms / Q000473:pathology