Table 2.

Differential diagnosis table for post-operative seromas and their salient imaging features.

	Mammography	Galactography	Ultrasound	CT	MRI
Seroma	Soft tissue density mass, may contain Ca++	Round mass communicating with the injected duct	Anechoic or hypoechoic round or oval mass	Round fluid density tissue mass, may demonstrate early contrast enhancement	T1W-hypointense, T2W -hyperintense May demonstrate early contrast enhancement at the margins, Delayed should not enhance
Hematoma	Round or oval mass, can show spiculation	No communication with duct	Anechoic to hypoechoic mass	High density mass	T1W- variable- based on age T2W- variable- based on age Contrast- No enhancement
Abscess	Ill-defined mass or focal asymmetry	May or may not communicate with duct	Hypoechoic, irregular mass	Low density mass Peripheral contrast enhancement	T1W-hypointense T2W- hyperintense Contrast- peripheral contrast enhancement
Papilloma	Often not visible Round or oval mass Course Ca++	Intraluminal filling defect	Intraductal mass Dilated ducts	Not visible	T1W- not seen T2W- hypointense mass in hyperintense duct Contrast- variable mild contrast enhancement
Invasive Ductal carcinoma	Round, oval, or speculated mass Microcalcifications	Intraluminal filling defect	Irregular, hypoechoic mass	Soft tissue mass	T1W- Isointense T2W- Hypointense Contrast- rapid, intense contrast enhancement