Cystic Ovarian Mass
Steven Bruch, M.D., Peter Strouse, M.D., Robert Ruiz, M.D.
Today’s case is a 15 year old girl who had a one week history of generalized achiness, back pain, dysuria, a sore throat, and fevers to 102 degrees. She was seen by her primary care physician who evaluated her with a rapid strep test that was negative, and a urinalysis that was positive for leukocyte esterase and blood, but nitrate negative.
She was treated for a urinary tract infection with Bactrim. Her fever resolved, but her symptoms remained unchanged prompting a visit to the emergency room for further evaluation. Her past medical history included attention deficit hyperactivity disorder, and depression. She was taking Imipramine and Concerta for these problems.
She had no prior surgery. Her physical exam was normal other than mild right upper quadrant tenderness, and fullness in the suprapubic area. An ultrasound revealed a cystic mass in the pelvis originally felt to be the bladder along with mild dilation of the right renal collecting system. A post-void ultrasound exam seen in figure 1 revealed the same cystic mass. A CT scan of the abdomen and pelvis with a Foley catheter in place revealed a large simple cystic mass (16 cm x 19 cm) most likely arising from the right ovary.
The left ovary appeared normal. Figure 2 shows the marked displacement of bowel gas out of the pelvis on the scout film of the CT scan. Select cuts from the CT scan shown in figure 3 along with views of the sagittal reconstruction show the cystic mass. Tumor markers, alpha fetoprotein and beta human chorionic gonadotropin, were normal.
|Figure 1 A-C. (A) Transverse ultrasound image just below the aortic bifurcation (arrows = common iliac arteries). The image was obtained after the patient had voided. A large cystic mass (M) fills the pelvis. No septae or solid components are seen. At the time of the ultrasound, the bladder was not identified separate from the mass, probably due to displacement by the mass. (B) Post void sagittal ultrasound image obtained at the level of the umbilicus shows the large cystic mass (M) filling the pelvis. (C) Longitudinal image of the right kidney shows mild collecting system dilation (asterisks).|
|Figure 2 A-B. AP (A) and lateral (B) CT scout images show a mass displacing air and contrast filled bowel out of the pelvis (large arrows). Some gas is present within the compressed bladder from Foley catheter insertion (small arrows).|
|Figure 3A-D. (A) Axial CT image just below the aortic bifurcation shows a large fluid attenuation mass (M) displacing bowel loops. As on the ultrasound, no septae or solid component of the mass are identified. Arrow = dilated right ureter. (B & C) Axial CT images in the pelvis shows the mass (M) filling the pelvis. The right ovary (B) appears to have acute or “beaked” margins adjacent to the mass (arrows) whereas the left ovary (C) has a normal ovoid shape (arrow). This suggests that the mass more likely arises from the right ovary than the left ovary. B = air in the bladder from Foley catheter insertion. (D) Sagittal reconstruction of the CT images. The mass (M) rises up out of the pelvis into the lower abdomen. The bladder (B), containing gas and urine, is displaced anterior and inferior.|
With the differential diagnosis including an ovarian cystic mass and a mesenteric cyst she was brought to the operating room for an exploratory laparotomy and excision of the cyst. A 4 cm incision was made in the suprapubic region. The cystic mass was identified through this small incision. It appeared to arise from one of the ovaries. In order to drain the cyst without risk of contaminating the peritoneal cavity, a plastic laparoscopic camera bag was fixed to the anterior wall of the cyst with Dermabond and then Bioglue.
A veres needle was then placed through a pursestring suture to drain the cyst fluid. 1600 cc of clear fluid was obtained and sent for cytology. The decompressed cyst was then brought out of the small incision and removed leaving the remaining right ovary and fallopian tube intact as shown in Figure 4.
|Figure 4. Intraoperative photo showing right ovarian cyst after 1600 cc of fluid was aspirated. This allowed the cyst to be brought out of a 4 cm midline suprapubic incision.|
She recovered nicely from this procedure and was discharged from the hospital the next morning.
Pathologic evaluation revealed a 16 cm by 16 cm by12 cm mass with some residual clear fluid inside. The remainder of the fluid that was removed in the operating room was examined cytologically and was negative for malignant cells. The cyst lining was smooth and white-tan in appearance. There was a small rim of ovarian tissue included with the cystic structure. The majority of the right ovarian tissue was left in-situ. The ovarian tissue that was removed demonstrated normal appearing ovarian stroma and some small ovarian cystic structures demonstrated in figure 5. The round ligament was included with the specimen and is depicted as fibromuscular tissue in figure 6.
|Figure 5. Sections of the residual ovarian tissue remaining on the cystic structure stained with hematoxalin and eosin. Figure 5A depicts normal appearing ovarian stroma with some scattered follicles. Figure 5B is a section through an area of the residural ovarian tissue that includes an ovarian cyst.|
|Figure 6. Fibromuscular tissue found on the outside of the cystic structure corresponding to the round ligament stained with hematoxalin and eosin.|
The inside of the cystic structure was lined with a cuboidal ciliated epithelium that mimics the structure of a normal fallopian tube. This is shown in figure 7.
Figure 7. Portion of the inside of the cyst wall stained with hematoxalin and eosin. The epithelial lining is made up of ciliated columnar cells similar in appearance to those seen normally lining the fallopian tubes.
The final pathologic diagnosis of this large cystic ovarian mass was a benign serous cystadenoma. Approximately 75-85% of ovarian neoplasms that require surgery in pre or perimenarcheal girls are benign. Ovarian cysts can be seen in the fetal / neonatal period, the premenopausal period, and in menstruating teenagers. The way the cyst is handled in each of these developmental groups differs.
Ovarian cysts are frequently seen on prenatal ultrasound examinations. These cysts are a response to maternal and placental hormones, and usually spontaneously involute. Up to 30% of female fetuses evaluated with prenatal ultrasound have ovarian cysts measuring more than 1 cm in diamenter, where only 1 in 100,000 female neonates will demonstrate ovarian cysts postnataly.
Neonatal ovarian cysts have almost no risk of malignancy, rarely cause symptoms, and are found either as mobile abdominal masses, or with ultrasound when following-up an abnormal fetal ultrasound exam. For treatment purposes, neonatal cysts are divided into four categories depending on the size of the cyst, (< 5 cm vs. > 5 cm), and the characterization of the cysts (simple vs. complex).
Small (<5 cm) simple cysts may be observed. Complex cysts of any size, and large (>5cm) simple cysts require intervention. The complex cysts often represent an ovarian torsion with hemorrhage, or, on rare occasion, are cystic structures that originate from other intraabdominal structures (intestinal duplications, omental cysts, etc.) The large simple cysts require treatment to avoid the increased risk of ovarian torsion. Either limited laparotomy or laparoscopy can be used to confirm the diagnosis, and decompress the cyst without sacrificing ovarian tissue.
Ovarian masses in prepubertal girls must be evaluated and treated as potentially malignant lesions. Functional ovarian cysts are very uncommon in this age group.
In the post- and perimenarchal girls, ovarian cysts are again common, and treatment is determined by the size and characterization of the cyst. These cysts are usually either follicular or corpus luteum cysts that result from the normal cycle of the ovarian follicles. Follicular cysts are the most common type of ovarian cyst, and should be considered abnormal if they are greater than 2 cm in diameter.
A normal physiologic follicle may be up to 2 cm in size. Corpus luteum cysts develop after ovulation, and are lined with lutenized theca and granulose cells. These often have a hemorrhagic appearance upon exploration. In the postmenarchal girl, a unilocular cyst less than 5 cm in diameter does not require surgical intervention. Resolution should be documented with follow-up ultrasound examination in 6-8 weeks. Again, larger simple cysts and complex cysts should be considered potentially malignant, and evaluated and treated appropriately. In childhood, ovarian tumors are the most common gynecologic malignancy.
These occur most commonly in the 10-14 year age range. The most common childhood ovarian tumors are the germ cell tumors (60-65%), with sex cord, stromal, and epithelial cell tumors making up the rest of the ovarian tumors. As the age range shifts to the 15-17 year range, the epithelial tumors make up a greater percentage of the ovarian tumors (~33%). Prior to surgical exploration of ovarian masses in this age range, tumor markers should be sent off preoperatively. These include alpha-fetoprotien, beta HCG, and CA 125 levels.
In this case there was a very large simple cystic structure that was 19cm x16cm that appeared to arise from the right ovary in a postmenarchal female. A simple cystic lesion of this size presents a controversy in management approach. The majority of these lesions will be benign in nature, but require a large incision to remove without decompression of the cyst.
Decompression, on the other hand, risks spillage of cyst fluid which may upstage the tumor from a stage I to a stage II tumor. Stage II tumors generally require treatment, in the form of chemotherapy, in addition to the surgical excision that is required for stage I tumors. To minimize the risk of cyst fluid spill, while using a small incision, a plastic barrier was glued to the cyst wall through a small lower midline incision.
A veres needle was then used to remove the majority of the cyst fluid so that the cyst could be easily delivered from the lower midline incision. The cyst was then removed leaving the residual ovary and fallopian tube intact. This technique combines the advantages of a small incision, (better cosmesis, less postoperative pain, fewer wound complications), with adequate control of the spillage from the tumor.
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