Langerhans Cell Histiocytosis with Initial Central Nervous System Presentation as a Mimic of Neurosarcoidosis

We report the case of a 58-year-old Caucasian woman who presented with a subacute cerebellar syndrome accompanied by disturbance of the hypothalamic–pituitary axis and was diagnosed with isolated neurosarcoidosis based on radiological findings including typically located cerebral lesions (infratentorial and pituitary stalk). Due to persistent clinical and radiological disease activity during several years despite escalation of immunosuppressive treatment, the diagnosis was reevaluated, and a transsphenoidal biopsy of a lesion at the pituitary stalk was performed revealing Langerhans cell histiocytosis. In this case, we discuss the different steps leading to the diagnostic error, as well as the presence of red flags, which should have led to an earlier diagnostic reevaluation.