Conventional criteria falls short with kids

Children are not small adults, even when it comes to the way they present with melanoma.

Kelly M. Cordoro, M.D., and colleagues recently reported on how common it is for children to present atypically with melanoma. Dr. Cordoro is associate professor of dermatology and pediatrics at the University of California, San Francisco.

The study, published June 2013 in the Journal of the American Academy of Dermatology, looks at whether using the conventional ABCDE criteria adequately detects the skin cancer in children.

Researchers conducted a retrospective study looking at 70 patients under age 20. Sixty of those were diagnosed with melanoma; the other 10 had ambiguous melanocytic tumors treated as melanoma. They divided patients into two groups by age at diagnosis, including an ages zero to 10 years group, representing 19 children, and an 11-to-19 years group.

“The 19 prepubertal patients in this study represent one of the largest series reporting detailed clinical and histopathological features of melanoma in this age group. Large national cancer databases and registries provide summary statistics such as age of presentation, melanoma subtype, site, treatment and outcomes, but lack detailed information about the presenting features and recent history of the melanoma,” Dr. Cordoro says. “This is critically important information for clinicians because we need to know what we should be looking for in order to not miss this diagnosis in children. In fact, 86 percent of children less than 10 years old in this study had a greater than six-month delay in diagnosis, most likely due to a low index of suspicion and atypical clinical presentations common to this age group.”

They found 60 percent of the younger group and 40 percent of the older children did not present with conventional ABCDE criteria. Rather, their lesions tended to be characterized by amelanosis, bleeding bumps, uniform color, variable diameter and de novo development, according to the study.

Not only were the clinical characteristics different but histopathological subtypes varied between groups. The histopathologic differences from adult melanoma identified in these patients seemed to parallel the non-ABCD morphology observed clinically, according to Dr. Cordoro.

Nearly half (44 percent) of the lesions were not classifiable by experienced dermatopathologists into conventional adult subtypes (e.g. superficial spreading, nodular, acral lentiginous, lentigo maligna). Very likely, the histopathological complexity of these lesions contributed to the diagnostic delay, she says.

More than 90 percent of the younger patients had stage 2a disease or higher, compared to 46 percent of the older children.

NEXT: Conventional ABCD criteria inadequate

Inadequate criteria?

The conventional ABCD criteria (asymmetry, border irregularity, color variation and diameter >6 mm) were largely inadequate for detecting melanoma in especially younger children. The “E,” for evolution, proved to be the more sensitive indicator, according to Dr. Cordoro.

“The criterion of evolution was universally valuable, capturing nearly 100 percent of the entire cohort of pediatric melanomas. We must remain mindful of this as we interview and examine our patients. Though growth is a form of evolution, nevi in children are often changing with age and dermatologists are very good at recognizing these banal transitions,” Dr. Cordoro says. “More important are new, persistent pink or red papules or nodules or pigmented nevi that have developed new symptoms such as itching, crusting or bleeding. The latter are warning signs, and warrant biopsy.”

The presentation of melanoma in children can mimic a benign pyogenic granuloma, according to Melinda Chu, M.D., resident and clinical trials fellow in the department of dermatology at Saint Louis University, St. Louis.

“In adults we generally think of melanoma as being a brown spot or coming from a mole, but in children it can be a skin-colored lesion that bleeds a lot that looks like a pyogenic granuloma,” Dr. Chu says.

Still, the modified criteria are not meant to replace the conventional ABCDs because many children will still present with typical melanomas, according to Dr. Cordoro. Rather, A for amelanotic; B for bleeding, bump; C for color uniformity; and D for de novo, any diameter are meant to raise awareness and serve as a reminder of the alternate presentations of melanoma in children, she says.

Reference:

Cordoro KM, Gupta D, Frieden IJ, et al. J Am Acad Dermatol. 2013;68