Endocrine Abstracts

A 65-year-old Caucasian gentleman was admitted with weight loss and generally feeling unwell. X ray chest done a week before admission as part of routine investigation by the General Practitioner, showed healing rib fractures with diffuse sclerosis. Malignancy was initially suspected due to the bony changes in the chest X-ray. Hence a full body CT scan was done and was normal. Incidentally he was noted to have low adjusted calcium of 2.16 mmol/l (2.20–2.60), raised parathyroid hormone (PTH) at 1189 ng/l (914–72), raised alkaline phosphatase (ALP) at 1189 μ/l (40–130) and low 25-hydroxy vitamin D levels of 15 mmol/l (24–167) consistent with vitamin D deficiency. He did not have any symptoms of hypocalcaemia such as perioral paraesthesia, numbness/tingling in the fingers, or muscle cramps. He was treated with high dose vitamin D replacement of 20 000 IU capsule once a week and calcium carbonate 1.5 g tablet twice a day for 8 weeks. X-ray of his hands revealed evidence of short third and fourth metacarpals of both hands. Significantly raised PTH levels could not be explained by vitamin D deficiency alone; hence pseudohypoparathyroidism (PHP) was also suspected based on the clinical finding of the third and fourth metacarpals. Once he was vitamin D replete he received maintenance dose of calcium carbonate and colecalciferol one tablet daily. PHP is a very rare condition and often diagnosis is missed or delayed due to absence of typical physical signs and biochemical features mimicking vitamin D deficiency. It remains a diagnostic challenge. Signs and symptoms vary from person to person. Calcium is mobilized from the bone and hence patients remain relatively asymptomatic. Our patient was minimally affected by the biochemical abnormality and was in his mid-sixties when a diagnosis of PHP made. Appropriate interpretation of biochemical results along with good history taking and physical examination is crucial in diagnosing PHP.