Differential Diagnosis for a 53-Year-Old with Initial Positive Pregnancy Test, Now Negative, Without Bleeding, and with Abdominal Pain

• Single Most Likely Diagnosis
  • Ectopic Pregnancy: Although the pregnancy test is now negative, an initial positive followed by a negative result can occur in ectopic pregnancies due to the rapid decline of hCG levels. The absence of bleeding and the presence of abdominal pain are red flags for an ectopic pregnancy, especially in a woman of this age group where the risk is higher due to potential decreased fertility and increased risk of ectopic implantation.
• Other Likely Diagnoses
  • Miscarriage: A spontaneous abortion could explain the initial positive pregnancy test followed by a negative test. However, the absence of bleeding makes this less likely, though it's still a consideration, especially if the miscarriage was very early.
  • Pituitary or Ovarian Tumor: Certain tumors can produce hCG, leading to a false-positive pregnancy test. Abdominal pain could be related to the tumor itself or to other abdominal issues.
  • Gastrointestinal Issues: Conditions like appendicitis, diverticulitis, or bowel obstruction could cause abdominal pain and might be considered, especially if there are other symptoms like fever, nausea, or changes in bowel habits.
• Do Not Miss Diagnoses
  • Ovarian Torsion: This is a surgical emergency that can cause severe abdominal pain. Although less common, it's crucial to consider, especially if the pain is sudden and severe.
  • Ruptured Ovarian Cyst: Similar to ovarian torsion, a ruptured cyst can cause acute abdominal pain and is a condition that requires prompt medical attention.
  • Ectopic Pregnancy (Repeated for Emphasis): Given the initial positive pregnancy test and abdominal pain, ectopic pregnancy is a critical diagnosis not to miss due to its potential for severe consequences, including death.
• Rare Diagnoses
  • Choriocarcinoma: A rare type of cancer that can produce hCG, leading to a positive pregnancy test. It's more commonly associated with prior pregnancy, miscarriage, or molar pregnancy but could be considered in the differential for a false-positive pregnancy test and abdominal pain.
  • Phantom Pregnancy (Pseudocyesis): A condition where a woman believes she is pregnant along with some physical symptoms, but without an actual pregnancy. This is rare and usually associated with psychological factors.