Adrenal gland cancer. Light micrograph of a section through the inner region (medulla) of an adrenal gland tumour. The malignant (cancerous) tumour (neoplasm) is a neuroblastoma. The tumour cells are small and undifferentiated, with large dark nuclei that are surrounded by a narrow irregular rim of cytoplasm. Characteristic rosette-shaped arrangements of tumour cells surrounding a nerve fibre (neurofibril, pink) are seen (centre). The adrenal glands are located on the surface of the kidneys, and they release hormones such as adrenaline. Neuroblastomas mainly affect young children. Magnification unknown.