A 37-year-old woman presents to her family doctor with a painful enlarging right groin mass. She has no prior pelvic surgery, no history of trauma and her serum beta-HCG level is unknown.
The abnormality of the above CT scan most likely represents:
a) ectopic pregnancy
b) femoral hernia
c) ovarian dermoid (teratoma)
d) inguinal hernia
e) exophytic fibroid
There's a 3-cm inhomogeneous fat density mass lesion in the right groin subcutaneous soft tissue (an-terior to the right pubic bone, white; long arrow). It's medial to the femoral artery and vein (round structures just deep and lateral to it in sub-Q fat; short arrow). It's also associated with fat stranding in keeping with inflammation.
The most correct answer is: (b) femoral hernia.
These hernias occur just below the inguinal ligament, through a naturally occurring weakness called the femoral canal. Femoral hernias are more common in women (4:1), usually elderly and frail, al-though they can happen at any age, including in children. They typically present as a groin lump. Cough impulse is often absent. The lump is more globular than the pear-shaped lump of the inguinal hernia (which is far more common in men, 25:1). The bulk of a femoral hernia lies below an imagi-nary line drawn between the anterior superior iliac spine and the pubic tubercle (which essentially represents the inguinal ligament), whereas an inguinal hernia starts above this line. It occurs medial and adjacent to the femoral vein and usually contains peritoneal and greater omental fat, and some-times bowel loops (in this case, only fatty tissue is present in the hernia, no bowel).
Important take-away point: the potential for incarceration and strangulation in femoral hernias is higher than for all other hernias combined! Thus, a high index of suspicion needs to be maintained in acute onset of a tender groin mass. CT scan is the imaging modality of choice.
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