Differential Diagnosis
The provided CT scan of the abdomen and pelvis reveals several findings that can guide us towards a differential diagnosis. Here's an organized approach based on the given categories:
- Single Most Likely Diagnosis
- Ovarian cyst: The presence of a cyst-like low-density solid lesion in the left adnexa, measuring 2.5 x 2 cm, which appears unchanged compared to the prior study, makes an ovarian cyst the most likely diagnosis. The fact that it has not changed in size or appearance over time suggests a benign nature.
- Other Likely Diagnoses
- Diverticulitis: Although the CT scan does not show evidence of diverticulitis, the presence of scattered diverticula in the rectosigmoid colon makes it a possible diagnosis if the patient presents with symptoms such as abdominal pain or changes in bowel habits.
- Hernia complications: The tiny ventral midline abdominal hernia containing minimal herniation of fat into the subcutaneous tissues could potentially lead to complications such as bowel obstruction or strangulation, although there is no evidence of these complications on the current scan.
- Do Not Miss Diagnoses
- Ovarian torsion: Although the ovarian cyst appears benign, ovarian torsion is a potentially life-threatening condition that requires immediate attention. The presence of a cyst increases the risk of torsion, and any sudden onset of severe abdominal pain should prompt further investigation.
- Bowel obstruction: The anastomotic changes in the bowel in the left lower quadrant could potentially lead to bowel obstruction, which is a medical emergency. Although there is no evidence of obstruction on the current scan, any signs of obstruction, such as severe abdominal pain, vomiting, or constipation, should be thoroughly investigated.
- Ectopic pregnancy: Although the patient's reproductive history is not provided, an ectopic pregnancy could present with similar symptoms and should be considered in any female patient of childbearing age with abdominal pain and a cystic adnexal mass.
- Rare Diagnoses
- Ovarian malignancy: Although the cyst appears benign, there is always a possibility of ovarian malignancy, especially if the patient has a family history or other risk factors.
- Gastrointestinal stromal tumor (GIST): The anastomotic changes in the bowel could potentially be a GIST, although this is a rare diagnosis and would require further investigation, such as a biopsy or additional imaging studies.