LCH : Prognosis

Comments:
Prognosis of Langerhans Cell Histiocytosis (LCH): The clinical course depends upon the stage at presentation. Patients with unifocal LCH have an excellent prognosis with a >99% survival rate. Some cases of unifocal LCH progress to multisystem involvement, usually in infants.

The outcome of multifocal disease is as follows: 30% achieve complete remission, 60% develop chronic LCH, and 10% have fatal outcome. Young children with multisystem disease who do not respond to initial therapy have a mortality of about 66%.

Involvement of bone marrow, liver, and spleen are adverse prognostic factors. Patients who respond to induction chemotherapy do better (overall survival around 90%) than non-responders (overall survival 17-34%). BRAF inhibitors such as vemurafenib have shown good results, although BRAF V600E mutations seem to have no impact on prognosis.

Long-term follow-up is necessary as some patients can develop complications such as hypothalamo-pituitary dysfunction, cognitive impairment, and cerebellar deficits.

This image of adult pulmonary LCH shows a late lesion consisting of a fibrotic nodule surrounded by traction emphysema.