Multisystemic recurrent Langerhans cell histiocytosis misdiagnosed with chronic inflammation at the first diagnosis: A case report.

Background: Langerhans cell histiocytosis (LCH) is characterized by diabetes insipidus and is an uncommon occurrence. Pathological biopsies still have a certain degree of diagnostic probability. We present a case in which LCH initially affected the pituitary gland. This resulted in a misdiagnosis of chronic inflammation upon pathological examination.

Case summary: A 25-year-old female exhibited symptoms of diabetes insipidus. Magnetic resonance imaging revealed an enhanced foci in the pituitary gland. After surgical resection of the pituitary lesion, the pathological diagnosis was chronic inflammation. However, the patient later experienced bone destruction in the skull and lower limb bones. After the lower limb bone lesion was compared with the initial pituitary lesion, the final diagnosis was modified to LCH. The patient was treated with multiple chemotherapy courses. However, the patient's condition gradually worsened, and she eventually passed away at home.

Conclusion: LCH should be considered when patients exhibit diabetes insipidus and absence of high signal intensity in the pituitary gland on sagittal T1-weighted image and abnormal enhancement in the pituitary region.