We present the case of a 26-year-old female patient with coincidental ultrasound finding of a neck tumour located below the left thyroid lobe. The tumour slightly increased in size over a year. Fine needle aspiration indicated the neuroectodermal origin of the tumour and surgical removal was performed. Although the tumour mass was carefully and successfully removed, post-operational Horners syndrome appeared. The tumour tissue was diagnosed as ganglioneuroma by histopathology.