Endocrine Abstracts

Introduction: Langerhans cell histiocytosis (LCH) is a neoplastic histiocytic disorder that characterized by proliferation of abnormal Langerhans cells. The most typical organs affected by LCH are the skin and bones, though it can also affect the pituitary gland, central nervous system, liver, spleen, lungs, and other organs.

Case 1: 36 year old man presented with polyuria, polydipsia and right hip pain lasting about 4 months. The pain increased in the last month. MRI of the hip resulted as lytic bone lesions. To further investigate a PET/CT was performed. PET/CT scan showed the patient had multiple lytic lesions on his left scapula, left maxilla, right 7-8-9th costae, T10-L1 vertebrae, sacrum, right iliac, right acetabular joint, and left ischium. A biopsy from one of the lytic bone lesions pathology is reported as LCH. In the fluid deprivation procedure, repeated urine tests showed no increase in the urine density, therefore the patient accepted as Central Diabetes Insipitus (CDI). The patient was prescribed 120 mg nasal desmopressin. Tests were not compatible with pituitary insufficiency. MRI of the pituitary revealed histiocytosis and stalk invasion. The patient recieved 12 cycles of cytarabine, 6 cycles of high-dose methotrexate and vemurafenib 2 x 960 mg as chemotherapy.

Case 2: 35 year old man presented with polyuria, polydipsia and was diagnosed as CD at 2016 and prescribed 2x120 mg nasal desmopressin. The patient reported back discomfort and jaw pain during the subsequent appointments in 2018 and 2019, respectively. In the year 2020 the pathology result of the molar tooth and mandibula came as LCH. The patient recieved six cycle of vinblastine and prednizolon as the initial chemotherapy. After 5 months of drug-free follow up, radiotherapy was administered to the iliac bone, right shoulder and mandibula. The patient’s symptoms do not improve in the following six months, and this is considered as disease progression. The patient then recieved eleven cycle of vinblastin 10 mg in the year 2021. The most recent PET/CT scan revealed remission of the illness. His pituitary functions were not compatible with pituitary insufficiency.

Discussion: Despite its rarity, LCH should be considered when making a differential diagnosis for patients who have central diabetes insipidus.

Keywords: Langerhans cell histiocytosis, Central Diabetes Insipitus