Melanoma and Melanocytic Tumors of Uncertain Malignant Potential in Children, Adolescents and Young Adults-The Stanford Experience 1995-2008

Abstract

Pediatric melanoma is difficult to study because of its rarity, possible biological differences in preadolescents compared with adolescents, and challenges of differentiating true melanoma from atypical spitzoid neoplasms. Indeterminant lesions are sometimes designated as melanocytic tumors of uncertain malignant potential (MelTUMPs). We performed a retrospective, single-institution review of melanomas, MelTUMPs and Spitz nevi with atypical features (SNAFs) in patients at 21 years of age and younger from 1995 to 2008. We identified 13 patients with melanoma, seven with MelTUMPs, and five with SNAFs. The median age for melanoma patients was 17 years, 10 for MelTUMPs, and six for SNAFs. Of the 13 melanoma patients, only four were younger than 15 years, while six were adolescents, and three were young adults. Nine melanoma patients (69%) were female. The most common histologic subtype was superficial spreading. The median depth for melanomas was 1.2 mm, and 3.4 mm for MelTUMPs. Microscopic regional nodal involvement detected on elective or sentinel lymph node (SLN) dissection was present in 2/10 (20%) of primary melanomas and 2/6 (33%) of Mel-TUMPs. Complete lymphadenectomy was performed on four melanoma patients, with three positive cases. Patient outcome through March 31, 2009 revealed no in-transit or visceral metastasis in patients with MelTUMPs or SNAFs. One SLN-positive patient (8%) with melanoma developed recurrent lymph node and liver metastasis and died 15 months after primary diagnosis. Our data highlight the rarity, female predominance, and significant rate of SLN positivity of pediatric melanoma. The high rate of MelTUMPs with regional nodal disease reinforces the need for close follow-up.

In Reply

“…We pointed out that this subgroup of tumors has a much more favorable prognosis than ''conventional'' melanomas and that the well-known, important prognosticators for conventional melanomas, such as tumor thickness and sentinel lymph node tumor-harboring status, do not appear to have the same significance for them. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] These facts support our proposal that such melanocytic tumors are biologically distinct and should be classified in a nosologic category separate from both melanomas and nevi.…”

“…[19][20][21] Although some of these previously reported, metastasizing Spitz nevi and blue nevi have since been reinterpreted as melanomas, 22,23 numerous large series with significant follow-up have highlighted the apparently favorable outcome of some ''borderline'' melanocytic tumors associated with regional lymph node metastases, such as atypical Spitzoid tumors and pigmented epithelioid melanocytomas. 2,5,[8][9][10][11][12][13][14][15][16][17][18]24 Despite this compelling evidence, Drs Sepehr and Tahan contend that even larger studies with longer follow-up are required before they will consider it appropriate to recognize additional, biologically distinct subgroups of melanocytic tumors. This begs the philosophic and rhetoric question, ''How much evidence is required to challenge accepted dogma and present new hypotheses that better explain the data?''…”

Increasing Incidence of Melanoma Among Young Adults: An Epidemiological Study in Olmsted County, Minnesota

“…6 Little is known about the natural history, distribution of subtypes, and disease-related mortality of melanoma among young adults. Studies addressing these issues have been unable to provide useful data because they are too small, 7 not performed in welldefined populations, 8 or biased by the underreporting and delayed reporting that characterize registrybased epidemiology studies. [9][10][11] Some studies 12 have suggested that younger age at the time of diagnosis of melanoma is correlated with increased risk of nodal disease.…”

Luteolin reduces the invasive potential of malignant melanoma cells by targeting β3 integrin and the epithelial-mesenchymal transition

“…The gradual increase of skin cancers has recently attracted worldwide attention [1] . Despite the relatively low incidence of melanoma, its mortality rates are the highest among all skin cancers [2,3] . The incidence of melanoma has increased steadily in Western countries and have doubled worldwide during the last two decades.…”