Primary hyperparathyroidism in a 14 year old girl presenting with bone deformities

A 14 year old girl with bilateral genu valgum of 6 years duration was brought for evaluation of primary hyperparathyroidism. She had clinical features of rickets such as frontal bossing, rachitic rosary, lumbar lordosis and fixed adduction deformity of the left leg. She had undergone osteotomy earlier for correction of these deformities without benefit. Laboratory investigations showed hypercalcaemia and hypophosphataemia, with elevated alkaline phosphatase and parathyroid hormone levels. A skeletal survey showed generalized decreased density of bone and brown tumours and, coincidentally, a right renal calculus. A computerized tomography scan of the neck and thallium-technetium subtraction scan delineated an adenoma of the left superior parathyroid gland, which was surgically removed. Parathyroid adenoma manifesting with bone deformities, especially genu valgum, is very rare in children. Early diagnosis and prompt treatment is essential to prevent such deformities.