IS Case 137: Oil cysts

Igor Mikityansky, MD, MPH

Imaging Sciences URMC 2008
Publication Date: 2009-05-21


Patient is a 51-year-olf female seen for evaluation of a firm palpable lump at the 12:30 o'clock position of the right breast for the past one month.


Coned-down tangential magnification view and 90 degree lateral view of the right breast were obtained after placing a radiopaque marker at the site of the tiny palpable lump that the patient feels in the 12:30 o'clock position of the right breast. At the site of the radiopaque marker, there are two superficial oil cysts. A third superficial oil cyst is seen slightly more inferiorly.

Ultrasound of the site of the tiny palpable lump at the 12.30 o'clock position about 3 cm from the nipple, there is a 1 cm, ovid, well-circumscribed, anechoic structure consistent with an oil cyst. Two additional oil cysts are noted in the adjacent area as well. These correspond to the mammographic abnormalities.


Oil cysts


The ovoid masses with central lucencies seen in this case are characteristic for oil cysts. The central lucency is due to liquefied fat. These lesions may be palpable or asymptomatic. They are frequently hypo- to anechoic round masses on ultrasound. Occasionally, they have mixed echogenicity, sharp capsule, rim calcifications, and mild posterior shadowing.

Steatocystoma multiplex, a rare genetic disorder, predominantly affecting males, demonstrates multiple intradermal cysts in the upper extremities and trunk.


  1. Conant EF, Brennecke CM. Case Review Series: Breast Imaging. Philadelphia: Mosby, 2006:66.

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