A 59-year-old female with 20-year history of slowly progressing muscle atrophy and sensory disturbance of upper extremities showed short stature, scoliosis, hunger type of sensory dissociation of the upper extremities and pyramidal tract sign of the lower extremities. Magnetic resonance imaging (MRI) clarified hypoplasia of the anterior pituitary lobe, Arnold-Chiari malformation and cervical syringomyelia. Insulin and arginine stimulating tests revealed partial type of isolated growth hormone (GH) deficiency but GH gene analysis detected no defects of GH genes. It was considered to be a rare case of non-hereditary hypopituitarism with Chiari malformation and syringomyelia not associated with perinatal injury, namely a midline anomaly syndrome.