Ultrasound scan in the diagnosis of scrotal swellings

An abscess is the end stage of acute or chronic inflammation or infection of the scrotum. If the infection affects the testes, there is severe pain and the scrotum is very tender and swollen. The image, here, shows a Power Doppler study of the affected testes. The testes is shows a cavity within it containing thick viscid fluid and membranous fibers (septae). Observe the marked increase in Color around it- this means there increased blood flow (hyperemia) in this organ. This is the sort of medical emergency that deserves immediate urological consultation- an acute scrotum.
See: http://www.ultrasound-images.com/scrotum.htm for more on this.

Inguinal hernia is one of the commonest causes of scrotal hernia in the male. In fact such hernias are truly inguino-scrotal swellings. This is because an inguinal hernia is the abnormal descent of the abdominal contents (intestine or bowel and intra-abdominal fat etc.) into the scrotum via a small canal (the inguinal canal) which connects the abdominal cavity with the scrotal space. Normally, this canal is sealed off by the tight canal. However, some conditions like chronic cough or straining while defecating (as in constipation), cause marked increase in intra-abdominal pressure forcing bowel etc into the scrotal sac (inguinal hernia).
Ultrasound imaging shows the bowel lying in an abnormal position, inside the scrotal sac, next to the testes. (See ultrasound image here).
Clinically this condition is easily suspected as the scrotal swelling increases on cough or straining. It usually reduces on lying down (recumbent position).
Surgery is essential to correct this condition.
Ultrasound image of hernia courtesy of Dr. Gunjan Puri, MD, India

The epididymis is a a small nodular structure that is normally present on the upper part of the testes, inside the scrotum. Cysts or collection of fluid inside a small bag / sac like tissue, are a common occurrence with the epididymis. These collections of fluid can sometimes large and cause alarm to the patient. Usually painless, the only symptom of this disease, is a swelling of the scrotum on the affected side. The ultrasound image (see image here) shows a large cyst of the left epididymis forming a large swelling above the left testes. The cyst in this ultrasound image measures more than 4 cms. in size and is in fact, larger than the left testes. In this case, the epididymal cyst is seen compressing the affected testes. A minor surgery is usually sufficient to remove this cyst and resolve the disease.

Inflammation of the testes is another cause of testicular and scrotal swelling. This disease is called orchitis. if the epididymis is also involved, the condition is labeled epididymo-orchitis. The patient is usually an adolescent or adult male with marked tenderness (pain on touching) and swelling of the affected scrotum. Typically, the pain is relieved when the testes is lifted up thus reducing the pulling down due to its own weight. The cause is usually infections by bacteria like E. Coli and Chlamydia Trachomatis. Sexually transmitted diseases like gonorrhea must also be excluded.
the attached ultrasound and Color Doppler image shows the appearance of inflamed testes. The most striking feature is the increased vascularity seen as color streaks all over the affected organ. Sonologists often call this testes on fire.

Neoplasm of the testes or masses or tumors of the testes can also be a cause of testicular or scrotal swelling. There are 2 types of scrotal tumor or swelling- intratesticular masses are usually malignant (cancerous) while extra testicular mass or tumors in the scrotum, that originate from outside the scrotum or testes are usually benign. In fact, if the tumor is found to originate from the testes (an this is easily done with modern high resolution sonography), the mass is cancerous unless proven to be otherwise. The commonest cancers of the testes are the so-called germ cell tumors (of which the commonest is the seminoma). These are usually seen in the male from 40 to 55 yr. age group. Another group where germ cell neoplasms occur are those with cryptorchidism or undescended testes. This is a disease, wherein the testes has failed to enter the scrotum and lies hidden in the abdomen.

The two ultrasound images/ pictures here show a typical cancer of the testes. Most of the left testes is replaced by dark area (the tumor) in the attached ultrasound picture. This represents the testicular cancer (germ cell tumor or seminoma). The normal testes is limited to a small rim of tissue along the bottom of the image. The patient typically has a painless swelling of the scrotum, usually on one side. The testes has a thick covering called the tunica albuginea, which usually seals off the tumour within the testes. Hence, less than 25 % of patients of seminoma or germ cell tumor have metastases or spread of tumor outside the scrotum.

Torsion of the testes usually occurs in adolescent boys from 12 to 18 yrs. age. The testes rotates on the spermatic cord (the cord that extends from the abdomen to the testes via the scrotum), resulting in disruption of blood supply to the testes. The provoking factors include sudden exertion or movement. In the color Doppler image shown here, the Right testes has become swollen and edematous with absence of blood flow to the organ. The left testis shows normal vascularity. This appearance is diagnostic of torsion of the right testes.

This ultrasound image shows both the testes proper (which are relatively normal) but there is marked thickening of the part behind the testes. This structure is called the epididymis and are markedly swollen (called edematous in medical parlance), with hyperemia (increased blood flow) (see more images of this case at: http://www.ultrasound-images.com/acute-scrotum.htm )
This patient has entered the stage of severe infection following untreated inflammation of the scrotum. The epididymis is a cord like structure behind the testes, which conducts sperms from the testicles to the spermatic cord and thence via the prostate to the penis. Inflammation of this part (the epididymis) is painful and has to be treated as soon as possible.