Sustained Clinical Remission of BRAF V600E-Mutated Langerhans Cell Histiocytosis With Multiorgan Involvement in an Infant Treated With Dabrafenib.

Background: Above 50% of LCH cases show BRAF-mutations, which can be targeted by dabrafenib in refractory disease.

Observations: Here, we report on a patient with neonatal multisystem, BRAF-mutated LCH refractory to conventional treatment with vinblastine and prednisolone. Duodenal involvement rendered oral nutrition impossible, and the patient was severely ill with pancytopenia, hepatic dysfunction, cholestasis, and septic episodes. After initiation of targeted therapy with dabrafenib, the patient achieved sustained clinical remission.

Conclusions: Multisystem LCH is a rare and potentially life-threatening disease that can mimic various neonatal conditions. A high index of suspicion is necessary for diagnosis. Timely initiation of targeted therapy may prevent irreversible organ damage.