Skeletal changes following growth hormone treatment in a child with combined hypopituitarism and a skeletal dysplasia.

A child with combined hypopituitarism and an undefined skeletal dysplasia is described. The hypopituitarism was manifested by post-natal growth failure, excessive sc fat, micropenis, and poor growth hormone response to provocative tests. Disproportionately short limbs, especially distally, and skeletal radiographs showing generalized brachydactyly, cone epiphyses of the phalanges and ossification defects in the proximal femoral metaphyses characterized the skeletal dysplasia. In contrast to the normal structure of the endochondral growth plate seen in hypopituitarism, the growth plate in this child was structurally abnormal; there was no differentiation of chondrocytes into hypertrophic and degenerative cells. Treatment with hGH for 8 months was associated with the appearance of chondrocyte differentiation, the restoration of growth plate structure to almost normal and a substantial increase in growth rate. There was no change in his disproportion or improvement in his radiographic abnormalities. These observations suggest that hGH may influence growth plate structure in certain instances and that this may be associated with increased linear growth.