Endocrine Abstracts

Case report: A 7-year-old girl presented with short stature following removal to the UK from China, where she had been diagnosed with GH deficiency on blood testing, for which GH treatment had been recommended. She had reportedly not grown well over the previous 2 years, and though the oldest in her class, she was the smallest. She had a poor appetite but otherwise was well. She had no constipation, normal activity levels, and was doing well in school. She was born at term weighing 2.9 kg.

On examination her height was 8 cm below the 3rd centile with a height standard deviation score of −3.6. Her weight was on the 3rd centile. She was proportional with no abnormalities of her chest or abdomen excepting some lichen planus on her trunk. She had no goitre and normal reflexes in her legs. Of note, she had marked calf muscle hypertrophy.

Investigations showed severe hypothyroidism with free T4 <3.9 pmol/l and TSH 1235 mU/l with positive thyroid peroxidise antibodies and bone age of 3.5 years. Thyroxine was initiated at 50 μg daily. By two weeks, her skin, previously dry, was improving, and by 3 months, her mother noted she was losing less hair and her calf hypertrophy was less noticeable. Her height velocity had improved to 5.6 cm/year.

Discussion: Proximal muscle weakness and hypotonia are well-recognised signs of hypothyroidism. The apparent muscle hypertrophy seen in our case is a rare manifestation of hypothyroidism, known as Kocher-Debre-Semalaigne syndrome.

Conclusion: Muscle pseudohypertrophy is a rare feature of hypothyroidism, which regresses with treatment. Hypothyroidism remains a cause of short stature, and should be excluded prior to a diagnosis of GH deficiency. It should be remembered as a rare differential of myopathy.