title: Malignant blue naevus with distant subcutaneous metastasis.
abstract: Malignant blue naevus is a distinct but rarely documented variant of malignant melanoma, and we describe the triple recurrence of a suprapatellar cellular blue naevus over 12 years in a middle-aged woman. Staging investigations revealed a distant subcutaneous metastasis of the right thigh. Immunohistochemistry of the primary lesion and all recurrences showed S-100, HMB-45, NKI/C-3 and Ki-67 positive cells. However, non-malignant cellular blue naevi from five consecutive other patients were all Ki-67 negative. The change from negative to positive Ki-67 responsivity may therefore be a valuable marker of malignant and metastatic potential in early cellular blue naevi.
authors.affiliation: Department of Dermatology, University Hospital of Zurich, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Böni
authors.forename: R
authors.initials: R
authors.lastname: Panizzon
authors.forename: R A
authors.initials: RA
authors.lastname: Huch Böni
authors.forename: H
authors.initials: H
authors.lastname: Steinert
authors.forename: R
authors.initials: R
authors.lastname: Dummer
mesh_terms: D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007866:Leg; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000473:pathology*; D018329:Nevus, Blue / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary*; D012878:Skin Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary*; D013848:Thigh; D014055:Tomography, Emission-Computed