The following lesions may resemble a figure of eight (sometimes referred to as snowman shaped):
supracardiac variety of total anomalous pulmonary venous return 1
pituitary macroadenoma with suprasellar extension 2
intraspinal neurofibroma with extraspinal extension through neural foramina
distal humerus in lateral x-ray elbow joint
collar stud abscess in the neck
inverted papilloma in the nasal cavity (extending into maxillary sinus through maxillary ostium)
esthesioneuroblastoma in the nasal cavity (extending intracranially through cribriform plate)