Giant congenital pigmented naevus or giant hairy n

Giant congenital pigmented naevus or giant hairy naevus

This hamartoma of naevo-melanocytes causes confusion because its definition and management are contentious. It has a similar histology to compound naevi, but with naevus cells distributed variably throughout all skin layers and into the subdermal fat and muscle and with a tendency to dermatomal distribution ( Figure 45.28 ). Giant congenital pigmented naevi (GCPNs) are precursors of melanoma but the magnitude of this risk is unclear, largely because of the lack of well-conducted studies and variable classification of the naevus. A 3–5% lifetime risk of melanoma is quoted. One in three childhood malignant melanomas arise in patients with GCPN, but the risk decreases with age: 15% of malignant melanomas present at birth, 62% present by puberty and 99% by 45 years of age. A multidisciplinary management approach is advocated, with initial investigations examining for neurocutaneous mela - nosis as there may be leptomeningeal involvement. Remov al of ed for both aesthetic and oncological GCPN should be consider reasons. Giant congenital pigmented naevus or giant hairy naevus

This hamartoma of naevo-melanocytes causes confusion because its definition and management are contentious. It has a similar histology to compound naevi, but with naevus cells distributed variably throughout all skin layers and into the subdermal fat and muscle and with a tendency to dermatomal distribution ( Figure 45.28 ). Giant congenital pigmented naevi (GCPNs) are precursors of melanoma but the magnitude of this risk is unclear, largely because of the lack of well-conducted studies and variable classification of the naevus. A 3–5% lifetime risk of melanoma is quoted. One in three childhood malignant melanomas arise in patients with GCPN, but the risk decreases with age: 15% of malignant melanomas present at birth, 62% present by puberty and 99% by 45 years of age. A multidisciplinary management approach is advocated, with initial investigations examining for neurocutaneous mela - nosis as there may be leptomeningeal involvement. Remov al of ed for both aesthetic and oncological GCPN should be consider reasons.