RESUMEN
BACKGROUND: Adult-onset Langerhans cell histiocytosis (LCH) with simultaneous involvement of the high cervical spine and the hypothalamus is rare. CASE DESCRIPTION: We have reported a case of adult-onset LCH in the second cervical vertebra with bony destruction and subsequent diabetes insipidus due to simultaneous involvement of the hypothalamus and pituitary stalk. Magnetic resonance imaging of the hypothalamus and pituitary lesion and immunohistochemistry of the cervical lesion revealed LCH. Posterior fusion of the cervical spine (first, third, and fourth cervical vertebrae) was performed, followed by systemic chemotherapy. The cervical fusion was well maintained, and the patient achieved clinical remission. No new LCH lesion was found during the follow-up of >2 years. CONCLUSIONS: Patients with known LCH of the spine showing new symptoms of diabetes insipidus should be examined for infiltrating lesions of the pituitary stalk or hypothalamus. In cases of severe instability of the spine, surgical treatment should be performed. If multiple and systemic LCH lesions are found, systemic chemotherapy should be administered.