Endocrine Abstracts

A 77 year old man developed a severe progressive polyneuropathy associated with significant disability. He was also found to have type 2 diabetes mellitus and antibody-negative primary hypothyroidism and was treated with gliclazide and thyroxine to good effect. Nerve conduction studies showed a demyelinating type neuropathy that was not typical of diabetic neuropathy. Two years later he was admitted with an episode of severe hypoglycaemia accompanied by low blood pressure, hyponatraemia and hyperkalaemia. A 250 microgram Synacthen test was abnormal (peak cortisol 316 nanomol per litre). A 1 milligram long Synacthen test was also abnormal (peak cortisol 476 nanomol per litre at 24 hours) and an 09.00 ACTH level was elevated (144 nanogram per litre). Serum electrophoresis revealed a 9 gram per decilitre IgG lambda monoclonal band but bone marrow examination was normal. Adrenal antibodies were negative and very long chain fatty acid levels were normal. Imaging revealed normal adrenal glands but a lesion with sclerotic margins between the second and third thoracic vertebrae. Biopsy revealed a carcinoid tumour that was felt to be an incidental finding. Treatment with physiological hydrocortisone replacement was commenced. Subsequently he was treated with high dose prednisolone for the neuropathy which resulted in a significant improvement in functional ability.
This case demonstrates the POEMS syndrome, with the endocrinopathy component comprising primary adrenal failure, primary hypothyroidism, diabetes mellitus and primary hypogonadism. The involvement of so many hormone systems is unusual and suggests that a circulating factor was interfering with some mechanism common to the endocrine systems affected. Other causes for adrenal failure and polyneuropathy, such as adrenomyeloneuropathy or a paraneoplastic syndrome, were excluded. The primary adrenal failure was life threatening and has only rarely been reported as a component of the POEMS syndrome.