hematology and oncology
Langerhans Cell Histiocytosis
Prognosis of Langerhans Cell Histiocytosis
Generally, patients with single system disease (unifocal, multifocal, and central nervous system [CNS] risk lesions) and multisystem disease without risk organ involvement are considered low risk. Patients with multisystem disease and risk organ involvement are considered high risk. Prognosis is good for patients with Langerhans cell histiocytosis and both of the following: Disease restricted to skin, lymph nodes, or bones Age>2 years Morbidity and mortality are increased in patients with multisystem involvement, particularly those with Age<2 years Involvement of risk organs (the hematopoietic system, liver, or spleen) Involvement of the zygomatic, sphenoid, orbital, ethmoid, or temporal bones denotes a category of CNS risk lesions that imparts a higher risk of neurodegenerative disease in the skull and front of the face. With treatment, the overall survival rate for patients with multisystem disease without risk organ involvement is 100%, but event-free survival is about 70%. Death is rare among patients with organ involvement who do not respond to initial therapy. Disease recurrence is common. A chronic remitting and exacerbating course may occur, particularly among adults. Some evidence suggests that patients who haveBRAFV600Emutations are more prone to relapses. 