Author
Information
Chawla
T*, Parulekar SV**, Fernandes G***, Rojekar A****.
(*Second
year Resident; ** Professor and Head, Department of Obstetrics and
Gynecology, *** Associate Professor, **** Assistant Professor,
Department of Pathology; Seth GS Medical College and KEM Hospital,
Mumbai, India.)
Abstract
There
are a number of causes of intramyometrial cysts, of which cystic
degeneration in leiomyoma is the most common one. Uterine leiomyomas
are predominantly composed of smooth muscle cells surrounded by a
pseudocapsule. An imbalance between oxygen demand and supply is
observed when leiomyomas enlarge, causing areas of degeneration.
Among the degeneration types observed, the hyaline, myxoid, red and
cystic degenerations are the most common. Intramyometrial cyst
formation is observed with cystic degeneration. Here
we describe a case of marked cystic degeneration of a uterine
fibroid, presenting as a large intramyometrial cyst.
Introduction
Intramyometrial
cysts can be due to cystic degeneration in a leiomyoma, adenomyosis,
congenital anomalies in the form of uterine cysts, cervical nabothian
cysts, and echinococcal cysts.[1,2,3,4,5] Uterine leiomyomas are the
most common benign solid tumors of the female genital system,
composed mainly of smooth muscle cells containing various amounts of
fibrous connective tissue. These tumors affect 20% to 30% of women at
childbearing age, and more than 40% of women above 40 years of age.
Cystic degeneration occurs in areas of hyaline degeneration when
extensive. It causes formation of a cysts within the
myometrium.[3,4,5] A case of a large intramyometrial cyst due to
cystic degeneration in an intramural leiomyoma is presented.
Case
Report
A
43 year old female married for 22 years, para 2 living 2 presented
with complaints of menorrhagia associated with dysmenorrhoea since 3
months. She would soak of 5-6 pads/day for 3-4 days during menstrual
flow. She had undergone laparoscopic tubal ligation 19 years ago. Her
medical or surgical history was not contributory. Her general and
systemic examination findings revealed no abnormality. The abdomen
was soft with a laparoscopic tubal ligation scar. The uterus was
enlarged uniformly to 16 weeks' size. A per speculum examination
showed a nabothian follicle on the cervix at 6 o'clock position, a
small rectocoele and lax perineum. There was no forniceal tenderness
or mass. Her biochemical preoperative investigations and chest
radiography were normal. Her hemoglobin was 6.5 g/dl for which she
received 4 units of packed cells transfusion, after which her
hemoglobin became 10.1g/dL. Abdominal ultrasonography revealed an
anechoic lesion in the posterior uterine wall, suggestive of a cystic
collection, measuring 5.0 × 4.0 cm in size. A
total abdominal hysterectomy was performed under spinal anaesthesia.
On further dissection of the specimen an approximately 6x4 cm of
fibroid was seen in the posterior uterine wall. When cut open it
revealed a unilocular cavity with amber colored fluid stained with
blood. A provisional diagnosis of cystic degeneration of the fibroid
was made with differential diagnosis of endometrial cyst.
Post-operative period being uneventful.
The
comprehensive histopathological examination of the specimen revealed
a large leiomyoma with extreme hyaline and cystic degeneration. The
leiomyoma was partly lined by endometrium on its external surface.
There was no evidence of any lining epithelium on the inner cystic
surface.
Figure
1. Showing gross specimen of uterus cut open showing leiomyoma. The
pseudocapsule of the leiomyoma is indented by pressure of the handle
of a scalpel, demonstrating fluid contents of the leiomyoma.
Figure
2. The leiomyoma with cystic degeneration has been cut open. Blood
stained fluid is seen escaping from the opening.
Figure
3. Showing gross specimen of uterus cut open with partially
enucleated leiomyoma, which has been cut open to reveal a smooth,
shiny inner surface of its cavity.
Figure
4. Showing a leiomyoma with extensive areas of hyalinization (red
arrows). No lining epithelium is seen on the inner surface of the
cavity of the leiomyoma (hollow arrow). (H&E x100)
Figure
5. Wall of pseudocyst without any lining epithelium (arrows). (H&E
x400)
Discussion
Leiomyomas
are the most common uterine neoplasms. They occur in 20-30% of women
in the reproductive age group.[3,4,5] They are composed of smooth
muscle and fibrous tissue and are benign in nature.[3] Based on their
location within the uterine wall, leiomyomas are classified into
submucosal/subendometrial, intramural/myometrial or subserosal
leiomyomas. Leiomyomas may outgrow their blood supply when they
enlarge, causing various types of degeneration; these include
hyaline, cystic, myxoid, fatty, infection, red degeneration,
dystrophic calcification.[5,6] Hyaline degeneration occurs in 60% of
leiomyomas.[3] Cystic degeneration is seen in 4% of leiomyomas. It
results in formation of cystic areas with solid contents, or a cavity
with irregular walls. Usually these areas are small and scattered. A
single large cystic cavity is unusual.[7,8] Such a cavity is not
lined by any epithelium and cannot be called a cyst. Hence we call it
a pseudocyst, though it is called as a cyst in published scientific
literature. Adenomyosis is another important cause of intramyometrial
cysts. Histopathology is diagnostic. Congenital anomalies in the
form of uterine cysts and echinococcal cysts are uncommon. The former
can be diagnosed on histopathology, while the latter can be diagnosed
on gross examination as well as histopathology.[7,8] Nabothian cysts
are diagnosed clinically by their location in the cervix and gross
appearance, and the diagnosis can be confirmed histopathologically,
if they are removed at all. The diagnosis of cystic degeneration of a
leiomyoma was confirmed on histopathological examination in our case.
Conclusion
Cystic
lesions are uncommon in the uterus. Cystic degeneration of leiomyoma
and adenomyosis are common causes of this condition. Usually these
are cysts are small, but occasionally they can be large.
Acknowledgement
We
than Dr Vijyeta Jagtap for the gross images of the specimen.
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Chawla T, Parulekar SV, Fernandes G, Rojekar A. Intramyometrial Pseudocyst. JPGO 2016. Volume 3 No. 4. Available from: http://www.jpgo.org/2016/04/intramyometrial-pseudocyst.html