Oil Cyst

• Liquefied fat
• Can be seen in any part of breast
• Most common in subareolar region
• Range from few mm to cm in size

Mammography

• Oval to round lucent smooth border lesion
• Develops rim calcification over time
• Calcification can be rim, egg-shell or coarse
• In early stages, same as surrounding fat and difficult to detect

Ultrasound

• Myriad of echogenicity – hyper, iso or hypo
• Can appear solid when inspissated fat present
• Sometimes can appear complex with mural nodules, septae

CT

• Calcified well circumscribed
• No enhancement

MRI

• T1 hyperintense
• Faint rim enhancement post Gd