Differential Diagnosis

The patient's symptoms of ongoing asymmetry below the costal margin of the R and L quadrants of the upper abdomen, which disappear when lying down and are non-fluctuant, tender to touch, and not consistent with a hernia, pose a diagnostic challenge. Given the history of multiple surgeries, including bilateral mastectomy, and normal labs with a non-revealing CT scan, the differential diagnosis can be organized as follows:

• Single Most Likely Diagnosis
  • Cutaneous nerve entrapment or neuroma: This condition could explain the tenderness and asymmetry, especially given the patient's history of multiple surgeries, which could have led to nerve damage or entrapment. The symptoms disappearing when lying down might suggest a positional component to the nerve irritation.
• Other Likely Diagnoses
  • Scar tissue or adhesions: Following multiple surgeries, the formation of scar tissue or adhesions could cause tenderness and asymmetry, particularly if these adhesions are pulling on the abdominal wall or internal structures in a way that is position-dependent.
  • Abdominal wall strain or injury: Given the patient's history and the nature of the symptoms, a strain or injury to the abdominal wall muscles could be considered, especially if the patient has been engaging in activities that could exacerbate such an injury.
• Do Not Miss Diagnoses
  • Ovarian torsion or other gynecologic emergencies: Although less likely given the patient's history of bilateral mastectomy (which does not directly relate to ovarian surgery), ovarian torsion or other gynecologic issues could present with acute abdominal pain and should be considered, especially if there's any possibility of residual ovarian tissue.
  • Intra-abdominal shunt or catheter malfunction: If the patient has any implanted devices (e.g., peritoneal dialysis catheter, intrauterine device, though less likely given the mastectomy), malfunction or infection could present with abdominal symptoms.
• Rare Diagnoses
  • Ehlers-Danlos syndrome or other connective tissue disorders: These conditions could lead to tissue fragility, poor wound healing, and potentially the symptoms described, though they would be less common and require further diagnostic evaluation.
  • Chronic abdominal wall pain syndrome: A condition characterized by chronic pain of the abdominal wall, which could be considered if other diagnoses are ruled out and the pain persists.

Each of these diagnoses requires careful consideration of the patient's history, physical examination findings, and potentially further diagnostic testing to determine the underlying cause of the symptoms.