Presentation
Involved in low-speed road traffic accident. 2 days later, has sudden onset abdominal pain. On examination, diffusely tender and guarding. Concern regarding traumatic abdominal injury with delayed presentation. Urine beta HCG test positive. Ultrasound showed large volume of free fluid and cyst in left adnexa. CT done as severely unwell.
Patient Data
There is a large volume of high density fluid throughout the abdomen in keeping with a hemoperitoneum. The solid organs enhance normally. There is a left adnexal "mass" with a central 3 cm cystic component. The periphery is hyperdense although it is not clear whether this is hematoma or enhancement of solid tissue. Findings consistent with ruptured left ectopic pregnancy.
Incidental finding of partially imaged, 20 mm hyperdense ovoid lesion centrally in left breast.
Hounsfield units (HU) are a measure of density on CT. Water has a HU of 0. Free fluid, often having some cellular material within it, has a HU just above 0. Fresh liquid blood has a HU slightly lower (30-45) than blood that has clotted (45-70). The clot is often a clue to as the site of bleeding (sentinel clot). Following a period of red cell lysis and clot organization, the HU measurement falls. A lower HU is also seen in anemia.
Case Discussion
The differential of a spontaneous hemoperitoneum in a young female is between ruptured corpus luteum cyst and ruptured ectopic pregnancy, with the beta HCG test being an important differentiator as they can look identical on imaging studies. At surgery, a ruptured fallopian ectopic pregnancy was confirmed.
The clinical presentation was muddied by the history of trauma 2 days earlier. This led to a consensus decision, which included the patient, to do a CT despite the positive pregnancy test in order to definitively exclude solid organ or bowel injury, and to aid in the surgical planning.
No follow up information regarding the left breast lesion has been provided by the clinical teams involved.
HISTOLOGY REPORT
Clinical history: Ruptured left ectopic pregnancy.
Macroscopic: Thin walled gestational sac with a small fetus with CR length of 22mm. Distorted fallopian tube with fimbrae measuring 75 x 15 x 15mm. An area of rupture is seen measuring 13mm in diameter.
Microscopic: Specimen is confirmed to be part of a gestational sac. Sections confirm a ruptured fallopian tube associated with chorionic villi and patchy inflammation within the fallopian tube wall. No evidence of gestational trophoblastic disease. Appearances are in keeping with the clinical history of a left tubal ectopic pregnancy.
Conclusion: Left tubal ectopic pregnancy confirmed.