Clinical features, diagnostic difficulties and therapeutic enlightenment of adult-onset multisystem Langerhans cell histiocytosis complicated with panhypopituitarism and central diabetes insipidus: a case report and systematic literature review.

Adult-onset Langerhans cell histiocytosis (LCH) involving the hypothalamic-pituitary region (HPR) is a rare and diagnostically challenging neoplasm, often presenting with severe neuroendocrine dysfunction. This report details the case of a young adult female who presented with panhypopituitarism and central diabetes insipidus (CDI) as the initial manifestation of multisystem LCH. The diagnostic journey, complicated by non-specific radiological findings mimicking common sellar pathologies, ultimately required histopathological confirmation via CD1a and S-100 immunohistochemistry. Management involved a multidisciplinary approach, yet the patient exhibited a suboptimal response to initial systemic chemotherapy, reflecting the refractory nature of adult multisystem disease. Partial remission was eventually achieved following salvage radiotherapy to the residual hypothalamic lesion. This case underscores the critical need to include LCH in the differential diagnosis of sellar masses with extensive endocrine dysfunction, highlights the diagnostic imperative of immunohistochemistry, and illustrates the therapeutic challenges and the enduring role of radiotherapy in managing refractory adult HPR-LCH, thereby contributing to the optimization of individualized management strategies for this complex disorder.