Acorn cyst sign is a

radiologic sign A radiologic sign is an objective indication of some medical fact (that is, a medical sign) that is detected by a physician during radiologic examination with medical imaging (for example, via an X-ray, CT scan, MRI scan, or sonographic scan). ...

indicating the presence of a

benign Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malig ...

uncomplicated

cyst A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubb ...

in ultrasound examinations of the breast. It consists of a deep anechoic fluid portion resembling an

acorn The acorn is the nut (fruit), nut of the oaks and their close relatives (genera ''Quercus'', ''Notholithocarpus'' and ''Lithocarpus'', in the family Fagaceae). It usually contains a seedling surrounded by two cotyledons (seedling leaves), en ...

, and a superficial echogenic layer resembling an acorn cap. This sign is helpful for radiologists to differentiate a benign uncomplicated cyst from a complex mass.

References

Radiologic signs Cysts Medical ultrasonography Breast imaging {{Neoplasm-stub