What is the most likely diagnosis for a patient with abdominal distension, vomiting, and a tender non-reducible swelling in the right groin below and lateral to the pubic tubercle, with X-ray findings of a distended small bowel with multiple fluid levels?

Femoral Hernia

The most likely diagnosis is A. Femoral hernia, based on the classic anatomical location below and lateral to the pubic tubercle, combined with signs of bowel obstruction and strangulation.

Anatomical Localization

The key distinguishing feature in this case is the precise anatomical relationship to the pubic tubercle:

• Femoral hernias present below and lateral to the pubic tubercle 1, 2
• In contrast, inguinal hernias (both direct and indirect) have their necks above and lateral to the pubic tubercle in 96.8% of cases 1
• This anatomical landmark is the most reliable clinical differentiator and has been surgically validated as an excellent CT reference point 2

Clinical Presentation Consistent with Strangulated Femoral Hernia

The clinical picture strongly supports a complicated femoral hernia:

• Tender, non-reducible swelling indicates incarceration or strangulation 3
• Abdominal distension with vomiting reflects proximal bowel obstruction 3
• X-ray findings of distended small bowel with multiple air-fluid levels confirm mechanical small bowel obstruction 4, 5
• The tympanic abdomen suggests significant gaseous distension from the obstruction 6

High Risk of Strangulation in Femoral Hernias

Femoral hernias carry a disproportionately high risk of complications:

• Strangulation rates reach 36% in emergency presentations, significantly higher than other groin hernias 3
• The incidence of incarceration and strangulation requiring emergency surgery is 86% in femoral hernias 3
• Strangulated contents may include small bowel (requiring resection in 16% of cases), omentum, or rarely other structures 3, 7
• Femoral hernias are more common in women and frequently present as surgical emergencies rather than elective cases 3, 7

Why Other Options Are Less Likely

Direct inguinal hernia (Option B) would present above and lateral to the pubic tubercle, not below it 1. Additionally, direct hernias rarely incarcerate due to their wide neck.

Indirect inguinal hernia (Option D) also presents above and lateral to the pubic tubercle 1. While indirect hernias can strangulate, the anatomical location described excludes this diagnosis.

Metastatic lymph node (Option C) would not cause mechanical small bowel obstruction with the classic radiographic findings described. Lymph nodes do not create a hernia sac containing bowel that becomes incarcerated 5.

Clinical Pitfalls to Avoid

• Femoral hernias are frequently misdiagnosed on initial presentation, leading to delayed treatment and increased morbidity 3
• The small size and location of femoral hernias can make them difficult to detect, especially in obese patients 3
• Emergency physicians must carefully palpate below and lateral to the pubic tubercle in any patient with groin pain and signs of obstruction 3
• Patients without regular physicians who lack routine physical examinations are at highest risk for developing strangulation 3

Immediate Management Required

This patient requires urgent surgical intervention given the signs of strangulation:

• The combination of non-reducible hernia, vomiting, and small bowel obstruction indicates strangulation until proven otherwise 4, 5
• Surgery should be performed within 24 hours of presentation to minimize bowel resection rates and mortality 3
• CT scan with IV contrast can confirm the diagnosis and assess for bowel ischemia, though it should not delay emergency surgery if strangulation is clinically evident 5, 2
• Delayed surgical intervention beyond 72 hours significantly increases morbidity and mortality 5