Congenital self‐healing reticulohistiocytosis with BRAF V600E mutation in an infant

Congenital self-healing reticulohistiocytosis (CSHR) is a rare disorder characterized by benign skin lesions with a tendency to self-heal. Multiple skin lesions are usually present in CSHR. It is very difficult to distinguish between CSHR and an invasive Langerhans cell histiocytosis. We present a case of a 5-month-old infant girl who had hypopigmented skin lesions distributed over her neck, thorax and torso. The skin lesions regressed spontaneously 2 months after the diagnosis of CSHR and the child has remained in complete remission without any sign of recurrence over a 2-year follow-up. BRAF V600E mutation was detected in lesional cells along with a low Ki-67 proliferative activity of about 6%. BRAF oncogene-induced senescence might contribute to a mechanism of self-regression in CSHR; however, the exact role of the somatic BRAF V600E mutation in CSHR remains to be determined.