Congenital or infantile melanoma

Congenital, infantile and paediatric

“Congenital” means presentation at birth; “infantile” refers to early infancy. Neither term covers all paediatric melanoma, which also includes older children and adolescents. These are exceptional and biologically heterogeneous conditions, so figures from very few cases cannot describe every situation.

A congenital melanocytic nevus is a benign lesion present at birth or recognised early, not melanoma by definition. An isolated small nevus and giant or multiple nevi have different risk contexts. Even a nodule within a congenital nevus may be a benign proliferation requiring specialist distinction.

Possible settings of origin

Melanoma may occur in association with a congenital nevus, especially in complex presentations, or without a recognisable nevus. Large or multiple nevi may also require consideration of neurocutaneous melanocytosis when clinically relevant. This does not mean every congenital nevus should be treated as a malignant tumour.

Transplacental transmission of maternal cancer cells is an exceptional possibility, distinct from inherited susceptibility. With advanced maternal melanoma, obstetric and paediatric teams determine placental assessment and newborn surveillance. Historical counts of six cases and claims of invariably poor outcomes do not represent the full available literature.

Xeroderma pigmentosum and immune deficiency or suppression may increase paediatric melanoma risk but are not obligatory causes of neonatal melanoma. Personal and family history guide appropriate investigations.

Assessing a suspicious lesion

Disproportionate growth, a persistently changing nodule, ulceration, bleeding or new symptoms warrant assessment. Normal childhood growth can also change a benign nevus, so change cannot be interpreted without context. Sites reported in small case series do not exclude lesions elsewhere.

Diagnosis requires collaboration between paediatric dermatology and expert pathology. Adequate biopsy, comparison with the surrounding nevus and selected molecular testing help distinguish melanoma from benign proliferative nodules. Spitzoid tumours are another group requiring careful classification; not every atypical lesion is melanoma.

Systemic investigations are chosen according to the diagnosis and clinical findings. An undocumented archive photograph cannot establish the patient’s age, lesion origin or a diagnosis of congenital melanoma.

Treatment and family support

Surgery is central to appropriate localised cases. Lymph node staging and additional treatment require dedicated paediatric decisions. Immunotherapy and targeted treatment may be considered in selected settings, taking account of age, molecular alterations, authorisations and available data. An adult protocol cannot automatically be transferred to a newborn.

Radiotherapy and chemotherapy may have individualised roles. Care should involve a centre experienced in rare childhood tumours, including psychological support and management of long-term effects.

Overall paediatric melanoma statistics cannot predict the behaviour of exceptionally rare congenital forms. Prognosis depends on origin, biology and extent. Families should receive a clear follow-up plan and guidance on changes to report without treating every mole as a source of alarm.