Differential Diagnosis for Abdominal Mass

• Single most likely diagnosis
  • Inguinal hernia: The mass is located in the left lower quadrant, lateral to the rectus abdominis muscle, and enlarges with Valsalva maneuver, which is consistent with an inguinal hernia. Inguinal hernias are more common in men and can be exacerbated by increased intra-abdominal pressure.
• Other Likely diagnoses
  • Femoral hernia: Although less common than inguinal hernias, femoral hernias can also present as a mass in the lower quadrant and may enlarge with Valsalva maneuver. However, they are typically located below the inguinal ligament and more commonly affect women.
  • Spigelian hernia: This type of hernia occurs through the spigelian fascia, which is located lateral to the rectus abdominis muscle. While it could be a consideration, spigelian hernias are less common and may not always present with the characteristic findings of an inguinal hernia.
• Do Not Miss diagnoses
  • Incisional hernia: Although the patient has no history of abdominal surgery, it's essential to consider incisional hernias, as they can be life-threatening if missed. However, the lack of surgical history makes this less likely.
  • Internal hernia: Internal hernias can occur through defects in the peritoneal cavity and may not always have a visible external mass. They can be life-threatening due to the risk of bowel strangulation.
• Rare diagnoses
  • Umbilical hernia: Typically located around the belly button, umbilical hernias are less likely given the location of the mass in the left lower quadrant.
  • Epigastric hernia: These hernias occur through defects in the abdominal wall between the xiphoid process and the umbilicus. They are less likely given the location and characteristics of the mass described.