Omental implantation secondary to ruptured tubal pregnancy with a negative urine pregnancy test: A case report

BACKGROUND: The first steps in the diagnosis of an ectopic pregnancy are to use a sensitive qualitative urine test to detect the β-subunit of human chorionic gonadotropin (β-hCG) and to perform a transvaginal ultrasonography. A negative urine pregnancy test result is generally used to exclude an ectopic pregnancy; however, a few studies have reported the presence of a ruptured ectopic pregnancy in a patient with a negative urine pregnancy test result. Furthermore, because secondary omental implantation (SOI) is rare and probably underestimated or misdiagnosed, a case of an SOI with a negative urine hCG test has never been reported. CASE: This was a very rare case of an SOI from a ruptured tubal pregnancy in a patient with an initial series of negative urine pregnancy tests and decreased levels of serum β-hCG. The SOI was managed with laparoscopy. CONCLUSION: For patients diagnosed with tubal or ovarian pregnancy who have negative urine pregnancy test results and decreased levels of serum β-hCG, lateonset omental implantation should be considered as a possibility.