Endocrine Abstracts

Introduction: Van Wyk-Grumbach syndrome was first described in 1960 in patients presenting with long standing juvenile hypothyroidism, delayed bone age and precocious puberty. Literature review indicates only few cases reported in males compared to females. We are reporting this case in a male patient who presented with short stature.

Case: A 7.25-year-old boy was referred for endocrine opinion due to short stature. He had not grown over the last 18 months. Further history revealed learning difficulties, constipation and tiredness for almost 3 years. Examination showed dry skin, dry hair, central adiposity, mildly hypertrophied calf muscles, and bilateral enlarged testicles (8 and 6 ml of right and left testicles respectively). Height was 107.3 cm (−3 SDS) and weight was 22.7 kg (−0.33 SDS). Bone age was 3.94 years. Biochemical evaluation revealed: TSH 1047 (0.3–3.8 mU/l) with undetectable free thyroxine (T₄), prolactin 1064 (0–350 mU/l), IGF 13.6 (12–62 nmol/l), cholesterol 9.26 (<4.40 mmol/l), ALT 118 (8–36 IU/l), creatinine kinase 495 (24–195 IU/l), and serum creatinine 70 (27–57 μmol/l). Synacthen test was normal and LHRH test revealed a pre-pubertal response. MRI pituitary showed a homogenously enlarged anterior pituitary with no interruption of the stalk or effect on the optic chiasm. Thyroid peroxidase antibodies were strongly positive. He was commenced on oral T₄ and his symptoms improved. Thyroid function and the abnormal biochemistry normalised in 6–8 weeks.

Discussion: High circulating TSH concentrations acting directly on FSH receptors has possibly led to proliferation of sertoli cells and testicular enlargement in our patient. Pseudo muscular hypertrophy could be associated with raised creatinine kinase. Enlarged pituitary gland is likely to be due to thyrotroph hyperplasia.

Conclusion: We present a rare case of long standing hypothyroidism with macro-orchidism and pituitary mass.