Differential Diagnosis for a 22-year-old Woman with Lower Abdominal Cramping and Vaginal Bleeding
- Single most likely diagnosis:
- Ectopic pregnancy: The patient's presentation of lower abdominal cramping, vaginal bleeding, and a positive urine β-hCG with no intrauterine gestational sac on transvaginal ultrasound is highly suggestive of an ectopic pregnancy. The presence of free fluid in the posterior cul-de-sac could indicate a ruptured ectopic pregnancy, which is a medical emergency.
- Other Likely diagnoses:
- Miscarriage: Given the patient's history of a recent menstrual period 7 weeks ago and the presence of vaginal bleeding, a miscarriage (either threatened, inevitable, or incomplete) is a possible diagnosis. However, the absence of an intrauterine gestational sac on ultrasound makes this less likely.
- Ovarian cyst rupture or torsion: The 1.5-cm unilocular right adnexal cyst could be related to the patient's symptoms, especially if it has ruptured or torsioned, causing pain and bleeding.
- Do Not Miss diagnoses:
- Ruptured ectopic pregnancy: As mentioned, this is a life-threatening condition that requires immediate attention. The presence of free fluid in the posterior cul-de-sac and the patient's symptoms could indicate a ruptured ectopic pregnancy.
- Ovarian torsion: Although less likely, ovarian torsion is a serious condition that can cause severe pain and requires prompt surgical intervention to preserve the ovary.
- Rare diagnoses:
- Molar pregnancy: Although rare, a molar pregnancy could present with vaginal bleeding and a positive β-hCG. However, the absence of an intrauterine gestational sac and the patient's symptoms make this less likely.
- Corpus luteum cyst rupture: This is a rare cause of acute abdominal pain and bleeding in pregnant women, but it could be considered given the presence of an adnexal cyst.