A 68 year old man was admitted nausea general malaise He was a hill farmer continued work his farm his sons on which he kept mostly sheep. Over last two weeks, since returning from Holiday in Spain, he had become increasingly fatigued. The only other symptoms of note were a 3 month history of poor appetite a 8 kg weight loss. He was receiving thyroxine 100 mcgm daily having diagnosed hypothyroidism by his GP 9 years previously. He was a smoker of 5 cigarettes per day had drunk more alcohol than usual whilst on holiday but usually drank about 12 units of alcohol daily. On examination, he was sun tanned, slightly confused, appeared dehydrated had a pulse of 92 bpm regular, a temperature of 37.2oC a pressure of 100/80 mmHg. Cardiovascular respiratory examination were unremarkable. He had a slight liver edge on palpation neurological examination was normal. Investigations revealed: Serum sodium 125 mmol/L Serum potassium 5.6 mmol/L Serum corrected calcium 2.73 mmol/L Serum standard bicarbonate 15 mmol/L Serum urea 22 mmol/L Plasma TSH 6 mU/L (NR 0.4 – 4.0)
Which of following likely diagnosis?
1 ) Bronchogenic carcinoma Syndrome of Inappropriate ADH secretion.
2 ) Hypoadrenalism
3 ) Hypothyroidism
4 ) Primary hyperparathyroidism
5 ) Sarcoidosis
Comments: This farmer a three month history of weight loss, anorexia fatigue. He recently returned from Spain but this a distractor as his occupation. The investigations show hyponatraemia, hyperkalaemia, uraemia, hypercalcaemia slightly elevated TSH which suggest diagnosis of Hypoadrenalism. He known have an autoimmune disease – hypothyroidism a diagnosis of Addison‟s suggested. Slight elevation of TSH a mild hypercalcaemia are typical of hypoadrenalism. Bronchogenic Carcinoma SIADH would be expected produce a hyponatraemia but potassium urea. The patient‟s symptoms do fit hypothyroidism (weight loss) uraemia hyperclacaemia would be expected. Although sarcoidosis may produce hypercalcaemia, hyponatraemia would be a typical finding respiratory signs may be expected. Primary hyperparathyroidism would produce such problems such a calcium concentration. 2 )