Differential Diagnosis for Vaginal Spotting and Positive Pregnancy Test
- Single most likely diagnosis:
- Ectopic pregnancy: The patient's presentation of vaginal spotting, positive pregnancy test, and lack of intrauterine pregnancy on ultrasound, combined with a slow rise in β-hCG levels, is highly suggestive of an ectopic pregnancy. The absence of chorionic villi on dilation and curettage further supports this diagnosis.
- Other Likely diagnoses:
- Miscarriage: Although the ultrasound did not show an intrauterine pregnancy, a miscarriage is still possible, especially given the patient's symptoms of vaginal spotting. However, the lack of chorionic villi on dilation and curettage makes this less likely.
- Pituitary or ectopic source of β-hCG: Although less common, a pituitary or ectopic source of β-hCG could explain the patient's positive pregnancy test and vaginal spotting. However, this would not typically cause a slow rise in β-hCG levels.
- Do Not Miss diagnoses:
- Molar pregnancy: Although rare, a molar pregnancy can present with vaginal bleeding and a positive pregnancy test. It is essential to rule out this diagnosis, as it can have serious complications if left untreated.
- Ovarian torsion: Ovarian torsion is a rare but life-threatening condition that can present with pelvic pain and vaginal bleeding. Although the patient does not have significant pelvic pain, it is crucial to consider this diagnosis to avoid missing a potentially deadly condition.
- Rare diagnoses:
- Persistent trophoblastic disease: This rare condition can occur after a miscarriage or ectopic pregnancy and can cause persistent β-hCG production and vaginal bleeding.
- Heterotopic pregnancy: Although extremely rare, a heterotopic pregnancy (a simultaneous intrauterine and ectopic pregnancy) can occur, especially in patients with a history of infertility treatment. However, this would typically be associated with a higher β-hCG level and more significant symptoms.