KAUAI, HAWAII – Every child diagnosed with medulloblastoma deserves a careful dermatologic evaluation for possible comorbid basal cell nevus syndrome, according to Jennifer Huang, MD, a pediatric dermatologist at Boston Children’s Hospital and Harvard Medical School.
“Medulloblastoma occurs in 10%-20% of patients with basal cell nevus syndrome and can be the presenting sign. So if a patient with basal cell nevus syndrome gets medulloblastoma, it usually occurs within the first year of life – and it can be the first thing you see,” she said at the Hawaii Dermatology Seminar provided by the Global Academy for Medical Education/Skin Disease Education Foundation.
Dr. Huang presented a series of pediatric dermatology clinical pearls focused not only on basal cell nevus syndrome (BCNS) and medulloblastoma, but also on the implications of skin-limited Langerhans cell histiocytosis, how to recognize and treat drug-induced follicular eruptions in pediatric patients on targeted anticancer therapies, and when to suspect Demodex folliculitis in immunosuppressed patients.
Skin-limited Langerhans cell histiocytosis
Around 10%-20% of patients with Langerhans cell histiocytosis (LCH) have the skin-limited form of the malignancy. These are patients who, after a thorough workup, have a normal CBC, skeletal survey, and liver function tests; essentially, no evidence of multisystem disease.
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Dr. Jennifer Huang
“It’s very rare for patients who present with skin-limited LCH alone to develop multisystem disease and to require chemotherapy or other more aggressive treatment,” Dr. Huang said. “I think that skin-limited LCH is probably a separate entity with its own natural history distinct from multisystem disease. We can see that with current genomic testing: in multisystem LCH, BRAF mutations are identified in at least half of patients, but very few with skin-limited disease express those mutations.
“The clinical pearl here is if you have a patient with skin-limited LCH it very rarely progresses to multisystem involvement. It’s associated with a good prognosis. That doesn’t mean you shouldn’t monitor them, but I think it can be reassuring information for the family,” she said.