Acute myeloid leukaemia presenting with diabetes insipidus.

A 41-year-old man was diagnosed with hypogonadotropic hypogonadism managed with gonadotropins after routine fertility review. Eight months later he presented with new polydipsia and polyuria, lethargy and easy bruising. A full blood count showed 28% circulating blasts. A bone marrow biopsy confirmed a diagnosis of acute myeloid leukaemia with inv(3)(q21.3q26.2) with additional monosomy 7. Central diabetes insipidus (DI) was diagnosed following a water deprivation test. Pituitary magnetic resonance imaging showed a slightly thickened pituitary stalk, stable Rathke's cyst, and new absence of the pituitary bright spot. The patient was commenced on desmopressin and induction chemotherapy, subsequently requiring a bone marrow transplant. Bone marrow examination at 100 days post-transplant revealed cytogenetic remission. All symptoms of DI resolved and magnetic resonance imaging showed return of the posterior bright spot and a pituitary stalk of normal thickness. Biochemical hypogonadotropic hypogonadism persisted but was uninterpretable in the context of systemic illness and recent chemotherapy. DI is a rare complication of haematological malignancies, and the prevalence and pathophysiology of DI in this context are poorly understood. Pathogenic mechanisms proposed include leukaemic infiltration of the pituitary, interference with antidiuretic hormone synthesis, and abnormal thrombopoiesis influencing hormone levels. Particular cytogenetic abnormalities such as inv(3)(q21.3q26.2) and monosomy 7 appear to be more commonly associated with DI and also appear to confer worse outcomes. Aetiologies in the literature remain elusive but as DI is a recognised association of haematological malignancies it should be considered in a patient presenting with polydipsia and polyuria.

Premenopausal women with early breast cancer treated with estradiol suppression have severely deteriorated bone microstructure.

BACKGROUND: In premenopausal women with early estrogen-receptor-positive breast cancer, combined ovarian suppression and aromatase inhibition reduce estradiol production precipitously. The resulting unbalanced and rapid bone remodelling replaces older bone with less bone that is less fully mineralized. We hypothesized that these changes result in severe microstructural deterioration and reduced matrix mineralization density. METHODS: Images of the distal radius and distal tibia were acquired using high-resolution peripheral quantitative computed tomography in a cross-sectional study of 27 premenopausal women, mean age 43.3years (range 30.4 to 53.7) with early breast cancer made estradiol deficient for 17months (range 6-120) using ovarian suppression and aromatase inhibition, 42 healthy age-matched premenopausal and 35 postmenopausal controls, mean age 62.6years (range 60.2 to 65.5). Cortical and trabecular microstructure were quantified using Strax software. RESULTS: Compared with premenopausal controls, the women with breast cancer had 0.75 SD (95% CI 0.21 to 1.29) lower distal radial trabecular bone volume due to 1.29 SD (0.71 to 1.87) fewer trabeculae. Cortical porosity was 1.25 SD (0.59 to 1.91) higher but cortical thickness was not reduced. Compared with postmenopausal controls 20years older, cases had comparable or lower trabecular bone volume and comparable cortical porosity and thickness. Matrix mineral density was 1.56 SD (0.90 to 2.22) lower than in premenopausal controls and 2.17 SD (1.50 to 2.84) lower than in postmenopausal controls. Results at the tibia were similar. CONCLUSION: The severe cortical porosity and trabecular deterioration associated with estradiol depletion and the longevity of premenopausal women with early breast cancer treated with endocrine therapy provide a compelling rationale to investigate the efficacy of antiresorptive therapy initiated at the time of breast cancer treatment.