Endocrine Abstracts

A 43-year-old lady with no significant PMH presented with recent onset of polyuria and polydypsia shortly after commencing an SSRI. Cranial diabetes insipidus was diagnosed on water deprivation test and good clinical response to DDAVP was seen. Anterior pituitary function was normal though prolactin elevated. MRI demonstrated a 4 mm enhancing lesion in the hypothalamus in association with a bright pituitary stalk. CXR was normal, ESR and serum ACE negative. The differential diagnosis included an inflammatory disorder or astrocytoma and close follow up was maintained. Amenorhea with low gonadotrophins and raised prolactin subsequently developed. Interval scans showed slow increase in size of the mass. The patient presented acutely with marked peripheral oedema, hypertension, proteinuria and acute renal failure. Renal USS showed bilateral renal obstruction with hydronephrosis due to retroperitoneal fibrosis. Stents were inserted, laporoscopy performed and omental and appendiceal biopsies obtained. These demonstrated chronic inflammatory changes and foamy macrophages. Following extensive consultation and review a unifying diagnosis of Erdheim–Chester disease was finally made. Cardiac abnormalities were subsequently identified and PPM inserted for tachybrady syndrome. Previously overlooked bone pain was investigated and osteosclerotic lesions typical of this condition were seen. Unfortunately immunosuppression with steroids and azathioprine had a poor clinical response and Type 2 diabetes mellitus developed. The patient is now on long term haemodialysis with progressive abdominal disease causing obstruction not amenable to further stenting. Recent MRI shows similar appearances of the hypothalamus but with new asymptomatic meningeal thickening.

Erdheim–Chester disease is an extremely rare non-Langerhans cell histiocytosis, characterised by xanthomatous and xanthogranulomatous infiltration which affects multiple organ systems. The prognosis is poor and few therapeutic options are available. Interferon therapy remains an option but has been declined by local funding bodies on the grounds of cost, lack of evidence from clinical trials and lack of experience in this condition by the attending physicians.