Enigma of the unusual pelvic mass: Lessons learnt
How to cite this article: Kale A, Lenin P, Livingstone YK, Chidambarnathan N. Enigma of the unusual pelvic mass: Lessons learnt. Case Rep Clin Radiol 2023;1:36-9.
Ruptured ectopic pregnancy (EP) is one of the common complications of early pregnancy. We are presenting a case of unruptured EP which presented as an ovarian mass on ultrasonography. Chronic ectopic pregnancies are very rare presentations that can present as hematosalpinx and can pose diagnostic challenges in cases with misleading clinical history and absent acute abdomen signs. In such cases, magnetic resonance imaging can be a problem-solving tool and can identify pathology, and helps in the prompt management of pathology.
Chronic ectopic pregnancy
Mimicking ovarian mass
Magnetic resonance imaging
Diagnosis of acute ruptured ectopic pregnancy (EP) is straightforward and is usually associated with a classical history of amenorrhea, pelvic pain and vaginal spotting, positive urine test, hemorrhagic ascites, and hemodynamic instability prompting urgent surgical intervention. Unruptured ectopic pregnancies are rare presentations, and clinical history may be misleading and can pose diagnostic challenges. We are presenting ultrasonography (USG) and magnetic resonance imaging (MRI) of such rare presentation.
A 27-year-old woman, gravida 1, para 1, abortion 0, presented with irregular bleeding for 2 months. There was no history of amenorrhea, no history of the acute abdomen, or use of any contraceptives. On examination, right fornix fullness was noted with no localized abdominal tenderness, guarding, or rigidity. On investigation, her Hb was 5 gm%, serum beta-hCG level – 595 IU/mL, serumCA-125 – 72.8 U/mL, and alpha-fetoprotein – 2.4 ng/ml.
USG of the pelvis revealed a complex heteroechoic adnexal lesion with no internal vascularity. There was no evidence of peripheral vascularity. Endometrial thickness was 5 mm with no evidence of any gestation sac or blood products. USG findings showed an adnexal lesion with no associated ascites [Figure 1]. In view of borderline elevated beta-hCG and CA 125 levels, MRI was ordered to characterize the lesion. MRI revealed a dilated tortuous distended tubal structure in the right adnexa, suggestive of a dilated fallopian tube. Contents of the tube showed heterogeneous signal intensity on T2, and hyperintense signal on T1 images with no fat suppression on FAT SAT images (not shown in images), representing blood products. Diffusion restriction was noted within the lesion. Post-contrast images showed minimal peripheral enhancement. No internal enhancement is shown. Both ovaries were seen separately from the lesion with the right ovary showing few simple cysts [Figure 2].
EP results from abnormal implantation of blastocyst outside the endometrium. Tubal EP (TEP) is the most common form of EP with the ampulla being the most common site. Chronic EP is a result of minor ruptures leading to subclinical hemodynamic insults. These events lead to episodes of leaking blood and gestation tissue into the peritoneum over a period of time. In few cases, ruptured ectopic may be contained locally to form a tubal hematoma without tubal rupture.
A TEP usually appears as a thick-walled cystic area typically showing a tubal ring sign, a very specific sign, on Doppler imaging. The absence of color Doppler flow does not exclude an ectopic. Various adnexal pathologies may present as an adnexal mass with the hemorrhagic component. In some cases, adnexal mass with the absence of classical sociological findings of an EP requires further investigation with an MRI, to establish a diagnosis.
Heterogeneous mass, hematosalpinx, hemorrhagic ascites, and tubal wall enhancement are common MRI features of TEP. GS-like component frequently contains foci of acute hemorrhage characterized as regions of intermediate to high signals on T1-weighted images. Ruptured TEP is often associated with hemorrhagic ascites which shows high signals on T1-weighted images. If the tube ruptures on the antimesenteric border side, then hemorrhagic ascites extends into the peritoneal cavity. Enhancing tree-like solid components representing fetoplacental tissues within a hemorrhagic mass may also be seen. Chronic EP rarely presents as an isolated hematosalpinx as seen in our case.
The dilated fallopian tube appears as a fluid-filled tubular structure arising in the region of the uterine cornua and occupying the adnexa. Unless the fallopian tube is fluid-filled or surrounded by fluid, it is not usually visualized on routine imaging. Incompletely effaced mucosal and submucosal plicae present as multiple incomplete folds or septae which is a characteristic feature of the dilated fallopian tube. These folds can be completely effaced in the overdistended fallopian tube. Tubal contents in a simple hydrosalpinx show a low signal on T1 and a high signal on T2 images, whereas hematosalpinx shows high signal intensity on T1 and T1 fat-suppressed images. The chronic presentation may be associated with pelvic adhesions involving the bowel, bladder, and ureter as an inflammatory reaction to pelvic hematoma.[2,6]
Identifying both ovaries separately from the lesion avoid misdiagnosing it as a multicystic ovarian tumor. One of the common causes of hematosalpinx is tubal endometriosis and it is often associated with the presence of endometriotic ovarian cysts showing T2 shading, features of adenomyosis in the junctional zone of the uterus, and the presence of T1 hyperintense pelvic deposits. Whereas, fallopian tube malignancy typically presents as a complex cystic solid enhancing adnexal mass. Whereas, a tubo-ovarian abscess shows diffusion restriction with peripheral enhancement. The main feature of tubo-ovarian torsion is ovarian enlargement due to venous/lymphatic engorgement, edema and hemorrhage with associated free pelvic fluid, reduced or absent vascularity, and a twisted dilated tubular structure corresponding to the vascular pedicle. Differential diagnosis is shown in [Table 1].
|Differential diagnoses list|
|Pelvic inflammatory disease/tubo-ovarian abscess|
Our patient underwent an uneventful laparoscopic right salpingectomy and adhesiolysis. Histopathology confirmed TEP. Timely management of EP reduces maternal mortality and improves fertility.
Either salpingotomy or salpingectomy is a treatment option available for an unruptured EP, where contralateral fallopian tube is healthy. Salpingotomy by laparoscopy has the advantage of shorter recovery time and fewer complications compared to salpingectomy by laparotomy but may be less likely to remove all the trophoblastic tissue. In practice, the choice of surgical option is influenced by surgeons’ experience and the patient’s own preferences.
Hematosalpinx in a woman with no intrauterine gestational sac and elevated beta-hCG levels, irrespective of the presence or absence of a clearly identifiable extrauterine gestational sac should raise a high possibility of an EP. Chronic EP can present as hematosalpinx and can pose diagnostic challenges in cases with misleading clinical history and absent acute abdomen signs.
Hematosalpinx can be due to various underlying pathologies. Careful pre-operative and intraoperative evaluation aids in correct diagnosis and helps in avoiding inappropriate treatment, such as hysterectomy with salpingooophorectomy. MRI proves a problem-solving tool in clinically stable patients, where further clarity of diagnosis is warranted.
What is first line of imaging investigation in diagnosis of ectopic pregnancy?
Combination of b and c.
Answer Key: c
What are causes of hematosalpinx?
Tubal ectopic pregnancy
Pelvic inflammatory disease
Fallopian tube carcinoma
All of the above.
Answer Key: e
Which of the following sonographic signs observed in acute ectopic pregnancy?
Tubal echogenic ring sign
Ring of fire sign
pseudogestational sac sign
All of the above.
Answer Key: d
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent.
Conflicts of interest
There are no conflicts of interest.
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