Endocrine Abstracts

Case history: We present a rare case of Langerhans cell histiocytosis (LCH) of pituitary stalk and hypothalamus in a 40 year old lady. She presented with 9 weeks history of a sudden onset of polyuria and polydipsia. She had extreme thirst even during night which led to significant nocturia and tiredness. She denied headache, blurring of vision, galactorrhoea or menstrual irregularity. She had no significant past medical history and was not on any medications. Physical examination was unremarkable.

Investigations and management: Basal pituitary profile was unremarkable. Short synacthen test, ESR, CRP, ACE and AFP were unremarkable. Water deprivation test was suggestive of central diabetes insipidus. Symptoms of DI responded very well to nasal desmopressin. Urgent MRI brain showed thickening of pituitary stalk. Biopsy was not needed at this stage. MRI after 6 months showed improvement in size of pituitary stalk swelling but prolactin level increased to 3600. Cabergoline 250 mcg twice a week was started. CT thorax, abdomen and pelvis were unremarkable. MRI whole spine showed multiple thoracic vertebral fractures and DEXA scan confirmed osteopenia. She was urgently reviewed with sudden onset headache and reduced visual acuity. MRI scan showed a sudden increase in the size of pituitary lesion which was now extending up into the third ventricle and hypothalamus and encasing the optic chiasm. Radiological differential included sarcoidosis atypical craniopharyngioma and pituicytoma. Pituitary profile showed panhypopituitrism therefore she was started on hydrocortisone and thyroxine. Autoimmune, Inflammatory, myeloma and lymphoma screening were negative. Biopsy of lesion was performed. Histology showed non necrotizing granulomatous chronic inflammation of suprasellar lesion. Differential diagnosis mainly included Rosai-Dorfman Disease and Langherans' cell Histocytosis. Final histological report confirmed the diagnosis of LCH. She developed hydrocephalous post biopsy and required VP shunt. Urgent radiotherapy was started to control the disease progression. Repeat MRI after competition of radiotherapy showed significant reduction in size of lesion. Three years following radiotherapy she remains stable with no evidence of local or systemic disease progression, although she remains hypopituitary and has significant hypothalamic symptoms.

Conclusion: Langerhans’ cell histiocytosis, localised in the hypothalamic–pituitary region is very rare, especially in adults. Diabetes insipidus is considered to be a hallmark of this condition. The gold standard for diagnosis of LCH is positive histology and immunohistochemistry evidence. Limited literature data show that low-dose irradiation (≤ 22 Gy) is usually the first-line treatment and adequate in most cases of isolated LCH of Hypothalmic Pituitary region.