Endocrine Abstracts

Introduction: Langerhans cell histiocytosis (LCH) is a very rare disease in adults and as well a very rare cause of sellar expansion. The clinical presentation can be heterogeneous, from a single bone lesion to potentially fatal, widespread disease. We describe the difficulties with the evaluation and the treatment of LCH.

Case: 39 years old woman has had amenorrhea for 2 years and higher intake of fluids (5–7 l/day) for 6 years. Non-functioning pituitary expansion with pituicytoma appearance was found on MRI. She was followed up for almost 3 years. Panhypopituitarism developed during the follow-up and replacement therapy with adiuretin, thyroxin and hydrocortisone was initiated. Finally, she underwent biopsy for slow progression of sellar expansion – Langerhans cell histiocytosis was confirmed histologically, with S100 a CD1a protein immunohistochemical positivity. Staging of the disease revealed suprasellar expansion, skeletal and retrobulbar infiltration, lymphadenopathy along the right internal carotid artery and retroperitoneal and mediastinal lymphadenopathy with FDG avidity on 18-FDG-PET/CT. She received five cycles of cladribine monotherapy with subsequent PET/CT restaging.

Discussion: Hypothalamus-pituitary-adrenal axis infiltration is present in up to 50% of LCH; the most common disorder is diabetes insipidus (DI). The frequency of DI is 30–40% and 94% if other pituitary hormone deficiencies exist. The diagnosis can be tricky. The primary treatment modalities for LCH include local excision of the lesion, corticotherapy, chemotherapy, radiotherapy, and imunnotherapy with anti-CD1a monoclonal antibodies. The data regarding the treatment of the central nervous system involvement with LCH are very limited. Cladribine (2-CdA) is a promising agent in this setting as previously reported. Cladribine has good bioavailability in the CNS. A total of six cycles of cladribine monotherapy can be administered with respect to the good profile of toxicity in this indication. However, prolonged neutropenia and respiratory infections led to premature termination of the treatment in our case.