zones between the various tissue components of the mass are characteristic of leiomyoma and may help differentiate it from other scrotal tumors. Fat containing tumors Lipoma Lipoma is the most common nontesticular intrascrotal tumor. It can be divided into 3 types depending upon the site of origination and spread: Originating in the spermatic cord with spread to the scrotum; Originating and developing within the cord (most common type) and Originating and developing within the scrotum. At ultrasound, lipoma is a well–defined, homogeneous, hyperechoic paratesticular lesion of varying size [Fig. 14]. The simple finding of an echogenic fatty mass within the inguinal canal, while suggestive of a lipoma, should also raise a question of fat from the omentum secondary to an inguinal hernia. However lipomas are well-defined masses, whereas herniated omentum appears to be more elongated and can be traced to the inguinal area, hence scanning along the inguinal canal as well as the scrotum is necessary to make the differential diagnosis. Magnetic resonance imaging and computerized tomography are helpful in doubtful cases. Liposarcoma Malignant extratesticular tumors are rare. Most of the malignant tumors are solid and have nonspecific features on ultrasonography. The majority of the malignant extratesticular tumors arise from spermatic cord with liposarcoma being the most common in adults. On gross specimen, liposarcoma is a solid, bulky lipomatous tumor with heterogeneous architecture, often containing areas of calcification. Although the sonographic appearances of liposarcoma are variable and nonspecific, it still provides a clue about the presence of lipomatous matrix. Echogenic areas corresponding to fat often associated with poor sound transmission and areas of heterogeneous echogenicity corresponding to nonlipomatous component are present. Some liposarcomas may also mimic the sonographic appearance of lipomas [Fig. 16] and hernias that contain omentum, but lipomas are generally smaller and more homogeneous and hernias are elongated masses that can often be traced back to the inguinal canal. CT and MR imaging are more specific, as they can easily recognize fatty component along with other soft tissue component more clearly than ultrasound. Adenomatoid tumor Adenomatoid tumors are the most common tumors of the epididymis and account for approximately 30% of all paratesticular neoplasms, second only to lipoma. They are usually unilateral, more common on the left side, and usually involve the epididymal tail. Adenomatoid tumor typically occurs in men during the third and fourth decades of life. Patients usually present with a painless scrotal mass that is