An unusual presentation of paraovarian cyst

Paraovarian cysts (POC) are benign tumors arising from adnexa occurring in women of reproductive age group. POC’s may be found at surgery or during an imaging examination that is performed for another reason. They are usually small and asymptomatic, large cysts as large as 20cms or more in diameter present to Emergency Department with acute abdomen. But our patient though was carrying tumor corresponding to 22 wks gravid uterus size was asymptomatic. As diagnosis of POC was not made pre operatively both clinically and radiologically, patient was taken for exploratory laparotomy. Histopathology proved to be mullerian duct cyst.


Introduction
Paraovarian cysts (POC) represent approximately 10-20% of adnexal masses (1) .They occur in women of all age groups, more common in women aged 30-40 years.Most of the time they are small and asymptomatic, although are occasionally large, resulting in pelvic pain (2) .A study in Italy has estimated their incidence to be about 3%.They are thin walled and unilocular, hence pose difficulty in differentiating it from ovarian cyst on imaging.There are no case reports of Mullerian duct cyst in females in literature.Hence we are presenting a case report which presented unusually.

Case History
A 23 years old nulliparous lady with a married life of 8 months presented with h/o 4 months amenorrhoea and Lower abdominal distension of 4 months duration.Her previous cycles were regular.She presented to us with Urine pregnancy test-negative (done in a private hospital) for evaluation of abdominal distension.
On examination, patient was well built and nourished with no pallor, pre operative weight of 76 kgs with height of 159 cm and BMI of 36.3 kg/ meter (2) .Hirsutism was present.On palpation mass arising from pelvis corresponded to 22weeks gravid uterus size and clinically measured 24x22 cms.It had cystic consistency, smooth surface, with horizontal mobility.On per vaginal examination Uterine not separately felt, all forniceal fullness present.Rectal examination revealed that the rectal mucosa and parametrium was free of nodularity or induration.Impression: Ovarian tumor or benign or malignant.
Paraovarian cysts can be seen at any age but are most commonly encountered in the third and fourth decades.In spite of causing rare symptoms, complications due to torsion, internal haemorrhage and rupture massive sizes are seen (5) .Cysts of Mullerian origin occurring separate from the ovaries and fallopian tubes are rare.Paraovarian and paratubal cysts are usually found in the mesosalpinx between the ovary and fallopian tube.These adnexal cysts may be classified as paratubal or paraovarian depending on their proximity to either the tube or the ovary (4) .Most adnexal cysts are presumed to arise from the ovary and are misdiagnosed as such and the definitive diagnosis of paraovarian cysts or paratubal cysts are commonly made at the time of surgery (2) .Clinically it is difficult to distinguish a paraovarian cyst from an ovarian cyst.Therefore imaging is frequently used to reveal the diagnosis.Besides this, sonographic diagnosis of such cysts is not always possible as it requires awareness and experience.Most patients (76%) with paraovarian cysts have a separate ipsilateral ovary which is seen by ultra sonography.However as per some studies paraovarian and paratubal cysts are difficult to diagnose before surgery with the use of transabdominal and

Paraovarian cyst Ovary
Right Fallopian tube

Ciliated columnar cells
transvaginal sonography as they may display follicle cysts, and suspicious findings (septations, papillations and solid components) because of close proximity to ovary (6) .On CT, most paraovarian cysts are unilocular, thin walled, and anechoic.Uncommonly, the cysts may show internal echoes and thin septations.Rarely, features suggestive of malignant changes such as papillary projections, mural nodules, or thick internal septations may be seen.Visualization of a normal ipsilateral ovary close to but separate from the adnexal cyst is an important MR finding.
Paraovarian cysts are rarely diagnosed by radiologists (2) .They should be considered in the differential diagnosis of acute abdomen in females.Paraovarian cysts are usually single, but bilateral lesions have been reported.Torsion of paraovarian cysts are usually seen in the reproductive age group especially in women having tubal ligation by Pomeroy method (8) .Paraovarian cysts are generally benign rarely they can be borderline or malignant.Both open surgery and laparoscopy have been advocated. (7).In our case as diagnosis was not made pre operatively open surgery was undertaken.Elevated LDH in our case could be due to other cause.

Conclusion
When a sonographic/CT study shows the ovary close to a pelvic cyst, paraovarian cyst should be one of the first diagnostic choices.Physicians should maintain a high index of suspicion for this uncommon cyst which is often difficult to diagnose both clinically and radiologically.

Fig: 1 -
Fig:1 -Pre operative paraovarian cyst of right side with tube