A rare skin lesion that usually involves the scalp, presents as a multinodular plaque > 2.0 cm, a history of progressive enlargement, often associated with a cellular blue nevus, and histologically characterised by a sheet-like growth pattern, mitoses, necrosis, and marked
cellular atypia. The behaviour of malignant blue naevi is unpredictable.
‘Garden variety’ cellular blue naevi may give rise to ‘benign metastases’ to regional lymph node in up to 5% of cases, but differ from true metastases in that the cells are cytologically benign. The late AB Ackerman weighed in on the subject and asserted that atypical blue naevus, malignant blue aevus, and metastasising blue naevus are merely evasive terms for what should be called melanoma.
Synonyms Atypical blue naevus, metastasising blue naevus
Reference Am J Dermatopathol. 2004 Oct;26(5):407-430