Simple Breast Cyst

Although most of these lesions are benign, the presence of a mass can cause significant anxiety because of the concern that the mass represents a cancer.

A mass can be solid or cystic and is not always seen on a mammogram.

An ultrasound can determine whether a breast mass is cystic or solid.

Cysts are most frequently seen in women who are 40 to 49 years old, but they may be present at any age.

Cysts are most often hormonally regulated and may occur in the perimenopausal period.

Cysts on ultrasound can be either simple or complex.

Ultrasound is 90% to 100% accurate for characterization of benign cysts when strict criteria are used.

Simple cysts have a negligible risk of cancer, and current evidence indicates that a simple cyst does not need to aspirated, unless it is symptomatic, and no other work-up is necessary.

Simple cysts on ultrasound are anechoic, well circumscribed, with smooth walls and posterior enhancement, as depicted in the image.

Complex cysts have a very low malignancy rate (0.3%) and a 6-month follow-up ultrasound is reasonable.

However, a complex cystic lesion with a significant solid component may have an associated cancer risk of up to 23%.

Therefore, if the mass has a solid component, a biopsy is indicated to rule out an associated malignancy.

References:

Berg WA, Campassi CI, Ioffe OB. Cystic lesions of the breast: sonographic-pathologic correlation. Radiology. 2003;227:183-191.

Morrow M, Wong S, Vetna L. The evaluation of breast masses in women younger than forty years of age. Surgery. 1998;124:643-640.

Osborne MP, Boolbol S, Asad J. Benign conditions of the breast. In Kuerer H (ed.): Breast Surgical Oncology. New York, NY: McGraw-Hill; 2010:165-179.

Venta LA, Kim JP, Pelloski CE, et al. Management of complex breast cysts. Am J Roentgenol. 1999;173:1331-1336.