An adult progressive Langerhans cell histiocytosis with central nervous system involvement for 10 years: A case report

INTRODUCTION: Langerhans cell histiocytosis (LCH) is a rare disease that usually occurs in children <15 years of age. Adult-onset LCH is extremely rare. Previous published guidelines and studies mainly focused on pediatric patients. The rarity and also insufficient knowledge of LCH in adults, especially central neuvous system (CNS) involvement of LCH, often resulted in missed and delayed diagnosis. CASE PRESENTATION: A 35-year-old woman presented with cognitive impairment, anxietydepression, decreased eyesight, skin rash, hypernatremia, gonadal hormone deficiency and hypothyroidism. She had experienced menstrual disturbance and infertility since 10 years ago. MRI examination showed a mass lesion in the hypothalamic-pituitary region. Sighs of radiologic neurodegeneration were not found on brain MRI scans, however. Biopsy of skin rash confirmed the the diagnosis of multisystem LCH. BRAF V600E mutation was detected in the peripheral blood mononuclear cells. She accepted combination chemotherapy of vindesine and prednisone and accquired partial remission. The patient died of severe pneumonia during the second course of chemotherapy. CONCLUSION: Given the complicated differential diagnoses of neuroendocrine disorders, it was essential to be aware of CNS involvement of LCH at first, especially in adults. BRAF V600E mutation may participated in disease progression.