SDMRad

 

Radiological Findings, Disease course and Management

 

                             

                               Pelvic Ultrasound                                                         

                                                                              

​

 

 

 

 

 

 

                                                                 

 

    Findings

• Left adnexal predominantly hypoechoic mass with linear echogenic   strands

                                                                     

                            CT Pelvis

 

  

 

 

 

                                                                        

 

 

               

 

 

 

 

 

  

​

 

 

 

 

 

 

 

 

 

Findings

• ​A well-defined peripheral wall enhancing lesion seen in the pelvis extending to the supravesical region.

• It shows hypodense contents with fat fluid level, calcification in          the wall and within the lesion, causing compression and displacement     of the bladder and adjacent bowel loops.

• Left ovary is not visualized separate from the mass.

 

Radiological Diagnosis

Left ovarian dermoid cyst

 

Disease Course and Management

Laparoscopic left ovarian cystectomy.

Dermoid cyst confirmed.

 

Discussion

• Mature cystic teratoma is a more appropriate term than “dermoid cyst” 

• Cystic tumors with tissue derived from at least two of the three germ cell layers (ectoderm, mesoderm, and endoderm).

• Affect a younger age group (mean patient age, 30 years), maybe bilateral 

• Mostly asymptomatic. Few patients suffer from abdominal pain or other nonspecific symptoms.

• Grow slowly at an average rate of 1.8 mm each year. 

• Surgical treatment -simple cystectomy. 

Diagnosis

Ultrasound

• US diagnostic in most cases.

• Variety of appearances. 3 manifestations:

1. Most common-cystic lesion with a densely echogenic tubercle (Rokitansky nodule) projecting into the cyst lumen.

2. Diffusely or partially echogenic mass with the echogenic area usually demonstrating sound attenuation owing to sebaceous material and hair within the cyst cavity.

3. Multiple thin, echogenic bands caused by hair in the cyst cavity

• Fluid-fluid levels result from sebum floating above aqueous fluid, which appears more echogenic than the sebum layer.

• Dermoid plug is echogenic, with shadowing due to adipose tissue or calcifications within the plug or to hair arising from it.

• Diffuse echogenicity caused by hair mixed with the cyst fluid.

 

CT 

• More sensitive for fat. At CT, fat attenuation within a cyst, with or without calcification in the wall, is diagnostic.

• A floating mass of hair can sometimes be identified at the fat–aqueous fluid interface

• Fat is reported in 93% of cases and teeth or other calcifications in 56%

​

MRI 

• Sebaceous component of dermoid cysts has very high signal intensity on T1-weighted images, similar to retroperitoneal fat. Signal intensity of the sebaceous component on T2-weighted images is variable, usually approximating that of fat.

• Combination of different signal intensities on T1- and T2-weighted images is not specific for fat and must be distinguished from MR imaging findings in intracystic hemorrhage.

• Hemorrhagic lesions like endometriomas may mimic the imaging appearance on T1- and T2-weighted images.

​

Complications 

• Rupture: Tumors can rupture, causing leakage of the liquefied sebaceous contents into the peritoneum resulting in granulomatous peritonitis. 

• Malignant degeneration: Squamous cell carcinoma arising from the squamous lining of the cyst is the most common type of malignant degeneration 

• Torsion (most common): Findings s/o torsion include

1. deviation of the uterus to the twisted side,

2. engorged blood vessels on the twisted side,

3. a mass with a high-signal-intensity rim on T1-weighted MR images, a low-signal-intensity torsion knot, and thick, straight blood vessels that drape around the mass and cause complete absence of enhancement  

​

References

• Outwater, E. K., Siegelman, E. S., & Hunt, J. L. (2001, March). Ovarian Teratomas: Tumor Types and Imaging Characteristics. Retrieved October 20, 2016, from http://pubs.rsna.org/doi/full/10.1148/radiographics.21.2. g01mr09475

​