Dermoid Cyst

Demographic and clinical details: 16 years old male, admitted with inguinal mass

Image Details; US image of right inguinal region shows the numerous floating echogenic focus in an anechoic cystic mass, This appearance which is called as sack of marbles sign, is caused by aggregations of multiple small globules of fat within a cyst mimicking marble spheres within a sack. This sign is considered highly suggestive finding of dermoid cyst in the head and neck region.

Dermoid cysts are lined by keratinizing squamous epithelium and consist of skin appendages such as hair follicles, apocrine glands, and sebaceous glands. They are usually diagnosed during infancy or early childhood and are commonly reported in the head and neck region. Dermoid cyst of inguinal region is a very rare condition.  

In my experience, USG is important in distinguishing solid lesions from cystic lesions of soft tissues. USG s better than MRI for discrimination of solid lesion from cystic lesion when it is  small and llocated in superficial soft tissues.

*Courtesy of Dr. Mehtap Balaban