Endocrine Abstracts

Background: Cushing’s syndrome (10-15/million people diagnosed/year) is quite rare with Cushing’s disease accounting for >70% of cases in adults. Spinal epidural lipomatosis (SEl) secondary to endogenous Cushing’s syndrome is even more rare condition (8 reported cases so far) of which 3 cases are secondary to Cushing’s disease. Here, we highlight a case of ACTH-dependent Cushing disease with resultant spinal epidural lipomatosis (SEl) that was treated with complete hypophysectomy leading to post-operative cranial Diabetes Insipidus.

Case: A 36-years old gentleman, background of asthma and ETOH abuse presented with sudden onset palpitations. He appeared cushingoid with moon face, facial plethora, central adiposity and purple abdominal striae and was referred to Endocrinology.

Investigations: Unsuppressed cortisol: 466nmol/lpost 1 mg overnight dexamethasone suppression test and 24hours urinary cortisol concentration was raised (928nmol/day). LDDST failed to suppress serum cortisol and confirmed Cushing’s Syndrome (CS). Unsuppressed random ACTH level: 190ng/l indicated ACTH dependent CS. MRI pituitary, rest of pituitary profile and CT adrenal was normal. Inferior Petrosal Sinus Sampling (IPSS) revealed central source with left sided gradient.

Management: He was commenced on block and replace therapy initially: metyrapone 250 mg TDS and dexamethasone 0.25 mg BD. During investigation, he developed lower limb weakness worsening over 4-5 weeks with no bowel/bladder symptoms. Being wheel-chair bound, he had features of thoracic myelopathy with grade 3/5 power, hyper-reflexia and clonus bilaterally. Sensations were reduced below T10-11 level with intact perianal sensation. MRI spine demonstrated diffuse excessive epidural fatty tissue posteriorly over his thoracic cord with spondylodiscitis at T11-T12. Generalised narrowing of thecal dimension, old superior end plate compression fracture at T11 and significant cord compression in thoracic spine was noted. Diagnosis was paraparesis secondary to Spinal Epidural Lipomatosis (SEl). Spinal MDT suggested treating conservatively with optimization of his Cushing disease, weight-bearing exercises and DLSO brace. Trans-sphenoidal complete hypophysectomy was performed as curative procedure. Post operatively he developed polyuria (8litres/day) and was commenced on DDAVP (Desmopressin 50 mg BD-100 mg BD) along with Hydrocortisone 20 mg/10 mg and thyroxine 50 mg OD. Currently he has post-operative pan hypopituitarism with cranial diabetes insipidus.

Conclusion: Early diagnosis and management of Cushing syndrome is imperative to prevent long term metabolic complications leading to increased morbidity and mortality. Spinal epidural lipomatosis is a very rare complication of Cushing syndrome and early optimization of Cushing syndrome remains vital to reduce neurological sequelae in these rare cases.