What is the most likely diagnosis for a 23-year-old woman, gravida 1 para 1, with a 4-cm ovarian mass, severe dysmenorrhea, and a history of pelvic inflammatory disease (PID), presenting with chronic right lower quadrant pain and right adnexal fullness?

Differential Diagnosis

• Single most likely diagnosis
  • Endometrioma: Given the patient's history of severe dysmenorrhea, pelvic inflammatory disease, and the presence of a 4-cm ovarian mass, endometrioma is the most likely diagnosis. The patient's symptoms and history are consistent with endometriosis, and the ovarian mass is likely an endometrioma.
• Other Likely diagnoses
  • Dermoid cyst: The patient's age and the presence of an ovarian mass make dermoid cyst a possible diagnosis. However, the patient's history of severe dysmenorrhea and pelvic inflammatory disease makes endometrioma more likely.
  • Ovarian cyst: A simple ovarian cyst is possible, but the patient's symptoms and history suggest a more specific diagnosis such as endometrioma.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Ovarian torsion: Although the patient's symptoms have been present for 2 months, ovarian torsion is a medical emergency that requires prompt attention. The presence of an ovarian mass increases the risk of torsion.
  • Ovarian cancer: Although rare in a 23-year-old woman, ovarian cancer is a possibility that should not be missed. The patient's symptoms and history do not strongly suggest cancer, but it should be considered in the differential diagnosis.
• Rare diagnoses
  • Mature cystic teratoma with malignant transformation: This is a rare complication of dermoid cysts, but it is possible in a young woman with an ovarian mass.
  • Germ cell tumor: These tumors are rare and typically occur in younger women, but they should be considered in the differential diagnosis of an ovarian mass.