Endocrine Abstracts

26year old Human rights activist being evaluated for left hip and thigh pain over the preceding 7 months, was referred to our services in November 2015 with headache, secondary amenorrhoea and raised prolactin levels. The headache which was mainly frontal started a few months ago and coincided with the amenorrhoea. She did not report visual disturbances or lactation. She also described the feeling of increased thirst and increased urinary frequency over this period. Apart from being investigated for the Left lower limb pain, she had no other past medical history. She attained menarche at the age of 12years. She had fairly regular periods initially, till she started taking oral contraceptives. The contraceptives were stopped due to the headache, but she remained amenorrhoeic. On Examination, her vitals were stable. She was not clinically dehydrated. She did not have any visual field defects. There was no milk expression or breast tenderness. Her blood tests at this clinic appointment showed raised prolactin levels (794mIU/l), secondary hypogonadism (Estradiol <92 pmol/l, FSH: 5.4 IU/l, LH: 5.4 IU/l), raised sodium levels (Na: 146 mmol/l) with correspondingly raised serum osmolality of 295mosm/l. The rest of her pituitary functions including IGF1, Thyroid and Cortisol were normal. Given her symptoms and test results, she went on to have a cannulated prolactin and a water deprivation test. These confirmed the raised prolactin and the presence of Cranial Diabetes Insipidus. Her MRI pituitary demonstrated the loss of the posterior pituitary bright spot, and thickening of the pituitary stalk. An inflammatory condition like Langerhans Histiocytosis was suggested. She was managed with Desmopressin and was referred for a full body FDG PET. This revealed the presence of heterogeneously increased tracer uptake around the proximal left femur, the bony cortex appearing thickened, irregular and moth-eaten. There was subtle tracer uptake in the pituitary. She then had a Left femoral tissue biopsy which confirmed the diagnosis of Langerhans cell Histiocytosis. She was reviewed in the haem-oncology MDM. Low dose femoral radiotherapy was suggested, which she underwent in February 2016. She then had pituitary radiotherapy in January 2017. Her femoral and pituitary lesions responded well to the Radiotherapy. She is currently being managed with hormonal replacement, Cabergoline and Desmopressin. She continues to be followed by our endocrine and haemato-oncology teams. Langerhans cell Histiocytosis is a rare infiltrative condition with unknown aetiology. Some genetic association with the BRAF and MAP2K genes have been identified.