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Cutaneous melanoma is extremely uncommon in children. Further, Asian-Americans appear to be at decreased risk for cutaneous melanoma. The authors present the case of a prepubescent Asian girl who presents with the rare spitzoid variant of cutaneous melanoma. The patient is a 4-year-old girl of Chinese descent who presented with a red, raised nodule, which increased in size over a 3-month period. She underwent wide local excision with sentinel lymph node dissection. On histopathologic analysis, she was found to have Spitzoid melanoma of childhood/adolescence. Spitzoid melanoma in children is rare and incompletely understood. A recent systematic review was only able to identify 82 such cases published over a 57-year period. To our knowledge, this is the first report of Spitzoid melanoma in a paediatric age patient of Asian descent. While this clearly is an uncommon demographic, it seeks to highlight important differences in racial predilection for Spitzoid melanoma.
Cutaneous melanoma is extremely uncommon in young children. One source estimates that prepubertal paediatric patients account for about 0.3% of all cutaneous melanoma diagnoses.1 Well controlled small series detailing the clinical presentation and prognosis of very young children diagnosed with typical cutaneous melanoma have only very recently been published,1 and as such a true comparison of these patients with the outcomes seen in adult and adolescent patients is based on only limited data.
There are clear racial differences in the incidence and clinical behaviour of melanoma. Based on data from the National Cancer Data Base, Shin et al reported that Asian-Americans represented 1237 of the 483 050 cutaneous melanoma diagnoses between 1986 and 2005, clearly suggesting an under-representation of these patients compared to the general population.2 Interestingly, Asian patients were more likely to have acral lentiginous melanoma, and to present with higher tumour stage compared to white patients, further suggesting a unique biology for these patients compared to Caucasians.2
The patient is a 4-year-old girl of Chinese descent, with her medical history significant for only asthma and no significant family history, including no history of melanoma or other skin cancer in first or second degree relatives. She was noted to have a new pinkish, red, raised nodule which was first noted 2–3 months before initial evaluation on the anterior portion of the right lower extremity, distal to the midline patella. The nodule was noted to grow rapidly in size and had become increasingly red, elevated and bled easily. On skin examination, she was noted to have a red flat scar 5 mm in diameter from the previous biopsy on the right lower extremity, in the anterior midline position, 5 cm distal to the midline patella. She had no abnormal nodularity or pigmentation and no other skin lesions were found. She had no palpable lymphadenopathy at either the cervical, supraclavicular, axillary, inguinal or popliteal regions bilaterally. Upon imaging, chest x-ray performed was clear.
This lesion grew to a diameter of 5 mm and was subsequently biopsied. Pathologic analysis showed Spitzoid melanoma, at least 3.0 mm in thickness, with focal ulceration and involvement of the deep margin, with immunohistochemistry reporting S100 and Melan-A positivity.
The patient underwent lymphoscintigraphy, with 980 uCi of technetium 99m sulphur colloid injected in divided doses around the melanoma site overlying the right upper anterior tibia. This identified a discrete lymph node in the proximal right femoral triangle and also a very faint lymph node in the right suprainguinal region, with at least two channels leading to the femoral lymph node.
She was then taken to the operating room for a wide local excision of the right proximal anterior leg melanoma biopsy site with a 1 cm radius margin. A circular excision of 2.4 cm longitudinally × 2.5 cm transversely was made with circumferential advancement of flaps of 2–3 cm used for complex primary wound closure. The right deep femoral selective sentinel lymph node dissection was also performed with intraoperative lymphatic mapping. On histopathologic analysis, there was residual focus of epithelioid cells, consistent with persistent focus of Spitzoid melanoma of childhood/adolescence, confirmed with S-100 staining (figure 1A–C). Presence of lymph node involvement in the submitted sentinel lymph node was noted on H&E staining (figure 1D). This was confirmed by immunohistochemical staining for S-100 protein, which demonstrated few microscopic nests of spindled cells in or near the subcapsular sinus in the node. These occupied about 5% of the total cross-sectional area of the node and were not present outside the capsule. Completion lymph node dissection revealed no evidence of melanoma in 4 suprainguinal lymph nodes and 11 femoral lymph nodes.
Subsequently, she was started on adjuvant treatment with interferon α-2B (starting at 20 million units/subcutaneous five times a week for 4 weeks, then tapering slowly over a 1-year course). She was free from evidence of recurrence via positron emission tomography scan on 1-year follow-up with no interval problems.
Spitzoid melanoma in children is rare and incompletely understood.5 A recent systematic review of the published literature on this topic, was only able to identify 82 such cases published over a 57-year period between 1949 and 2006.6 They reported a relatively favourable 88% 5-year survival rate in children less than 10 years of age and suggested that Spitzoid melanoma might represent a disproportionately larger subset of melanomas in children due to the overall lower incidence of other subtypes of cutaneous melanoma in children.6
To our knowledge, this is the first report of Spitzoid melanoma in a paediatric age patient of Asian descent. A recent large series of Spitzoid melanoma in children, published in 2009, reported 38 cases of histopathologically diagnosed Spitzoid melanoma in children, none of which occurred in Asian patients.7 The comparative rarity of cutaneous melanoma in children of Asian descent is further supported by a report of 73 paediatric aged patients with cutaneous melanoma treated at a single institution.1 They similarly found no Asian patients in this cohort, emphasising the rarity of Spitzoid melanoma in Asian children. The reason for these differences is unclear, however, given the relative lack of BRAF mutations, commonly seen in more common forms of melanoma, in Spitzoid melanoma, suggests a possible direction for further study.6
The overall incidence of regional lymphatic spread in paediatric Spitzoid melanoma has been estimated to exceed 70%.6 The exact clinical and prognostic significance of regional metastasis is unclear at present, however, given the relatively good survival in young children with this disease, it seems reasonable to suggest that it may portend less of an ominous prognosis in these patients, than it does in more common melanoma subtypes.
In summary, we present what to our knowledge is the first case of Spitzoid melanoma in a paediatric patient of Asian descent. While this clearly is an uncommon demographic for this disease, it seeks to highlight the important differences in racial predilection for Spitzoid melanoma in the paediatric age group.
Competing interests None.
Patient consent Obtained.