Metastatic Malignant Melanoma in Prepubertal Children

Abstract

Medical literature is full of involved and Confusing reports on the genesis, incidence, and development of metastatic melanoma in children. The reason for this confusion can be found in the early uncertainties that surrounded the real nature and correct diagnosis of metastatic melanoma in the prepubertal child. Before 1950, reports of melanomas with metastases in children were rare, poorly documented, and in many cases erroneous.1-4 In particular, benign nevi (now known as benign juvenile melanoma) went unrecognized and because of their alarming microscopic features were often diagnosed as malignant melanomas. For example, deceived by the predilection of this nevus for childhood, its frightening appearance, and failure to metastasize, Pack and Anglem wrote: ". . . . although malignant melanomas are found in infancy and childhood, they are of low grade malignancy and seldom metastasize" In a later paper, Pack6 coined the term "prepubertal melanoma" for those nonmetastasizing pigmented tumors of children which were microscopically indistinguishable from melanoma. He suggested removal before puberty when endocrinologic stimulation rendered certain of them capable of metastasis. Other investigators also noted this seeming disparity between microscopic appearance and clinical behavior.7 In 1948, Spitz8 provided the criteria for separating this unusual-looking nevus from malignant melanoma and termed it "juvenile melanoma." Later she and Allen9 showed that although these lesions are not restricted to children, they are much more common before puberty.* Subsequent authors10-13 have also classified juvenile melanoma among the benign nevi and the term spindle or epithelioid cell nevus10,12,13 is now preferred. McWhorter and Woolner13 in 1954 reviewed the subject of malignant melanoma in children and suggested that the favorable prognosis was spurious and due to the erroneous classification of spindle and epithelioid cell nevi under the former agnosis.

Malignant Melanoma Arising From a Giant Congenital Melanocytic Nevus in a 3-Year Old: Review of Diagnosis and Management

“…Melanoma arising from GCN has a worse prognosis than melanoma that arises elsewhere 4 . Trozak et al 16 performed a literature review of pediatric melanoma and found that none of 20 children whose tumors were associated with a GCN were alive after 5 years. This is attributed to melanoma in these lesions arising in the deeper dermis, 4,11 which makes early detection difficult and early spread by lymphatic or blood vessels more likely 4 …”

Congenital melanocytic naevi: An up‐to‐date overview

“…The deeper location also facilitates earlier spread through lymphoid vessels and blood vessels of greater calibre, leading to early metastasis. 45 In 24% of cases, the melanoma has already metastases at the time of the diagnosis. 44 One out of three melanomas develop primarily in the CNS in these patients, hence removing the CMN does not prevent the risk of death due to melanoma.…”

“…Rapid change and ulceration in congenital naevus are markers for the melanoma development 14,47 . Additionally, the rough, hairy, nodular surface of CMN masks the early observation of the tumour 45 …”

“…The deeper location also facilitates earlier spread through lymphoid vessels and blood vessels of greater calibre, leading to early metastasis 45 . In 24% of cases, the melanoma has already metastases at the time of the diagnosis 44 …”

“…10 Unfortunately, when a rare melanoma arises within a giant congenital melanocytic naevus, the prognosis is unfavourable. 45 This is because the cutaneous melanoma associated with giant CMN typically grows in the dermis makes it more difficult to detect. 46 Rapid change and ulceration in congenital naevus are markers for the melanoma development.…”