Melanoma presents differently in children, study finds

A new study suggests that childhood melanoma presents with peculiar features, which might make it trickier to diagnose than adult cutaneous melanoma.

According to the study, published in the March issue of Pediatrics, several cases may have clinical features resembling pyogenic granuloma and some cases may be amelanotic, according to Andrea Ferrari, M.D., Pediatric Oncology Unit, Istituto Nazionale Tumori of Milano, Italy

The study, Dr. Ferrari says, was born within the works of Pediatric Rare Tumors (TREP). Dr. Ferrari is co-chairman of TREP, launched nearly five years ago by the Associazione Italiana Ematologia Oncologia Pediatrica - Italian Association (AIEOP) on Pediatric Haematology Oncology.

"The definition includes a heterogeneous assortment of tumors, with a different biology, clinical history and site of origin; some of them being absolutely rare and others being rare in childhood but more common in adult age, such as cutaneous melanoma," he explains.

The authors' aims were to set up a clinical and pathological database; collect epidemiological data; define diagnostic and therapeutic recommendations; improve biological studies; and create a cooperation network with specialists involved in management of these tumors.

"The goal was to establish a background for the TREP chapter on melanoma; then, we sought to create data on diagnostic and therapeutic recommendations," Dr. Ferrari says.

In this retrospective single-institution study, researchers reviewed clinical and pathological data of all 33 patients from 3 years to 14 years, who were treated for cutaneous melanoma at Istituto Nazionale Tumori, during a 25-year period.

"Our hospital is a worldwide reference center for adult melanoma, and our unit is an international reference center for pediatric cancers," he says. "Our series includes only pre-pubertal patients, in order to clearly characterized childhood melanoma. This series is the largest reported series on childhood melanoma, when someone considers only pre-pubertal cases."

In about half of the cases, the patients' primary lesions were amelanotic; in 73 percent of cases, they were raised. The lesions occurred most often on the lower extremities, and, histologically, nine cases were classified as nodular, with 2.5 mm median thickness.

According to the study, nine children had nodal involvement at diagnosis - two were in-transit metastases and one was diagnosed with distant spread.

Surgery is mainstay Physicians at the hospital used surgery as the mainstay of treatment. Nine of the patients underwent lymph node dissection, three received chemotherapy and two received radiotherapy, according to the study's abstract.

"We also found that childhood melanoma seems to behave better than adult melanoma, but this is only a preliminary and speculative conclusion and more data are needed to confirm this," Dr. Ferrari says.

The authors reported 60 percent, five-year event-free survival and 70 percent overall survival. Event-free survival was 90 percent in children younger than 10 years and 47 percent in older patients.