23 year-old female presents complaining of progressive right lower quadrant pain after doing "vigorous" exercise. CT abdomen/pelvis below. What’s the diagnosis? ( Hint : it’s not appendicitis)

Rectus sheath hematoma

Rectus Sheath Hematoma (RSH)

Rectus muscle tear causing damage to the superior or inferior epigastric arteries with subsequent bleeding into the rectus sheath; uncommon cause of abdominal pain but mimics almost any abdominal condition.

Diagnose with CT, but try using ultrasound (thanks Dr. Joseph Minardi)

May occur spontaneously, but suspect with the following risk factors:

Coagulopathy (#1 cause); acquired (e.g., warfarin) or inherited disorder

Rectus muscle trauma

Vigorous or sudden contraction of rectus muscle

Increased intra-abdominal pressure from vigorous coughing

Pregnancy (gestation, labor, or post-partum)

Typically a self-limiting condition, but hypovolemic shock may result from significant hematoma expansion.

Hemodynamically stable (non-expanding hematoma): conservative treatment (rest, analgesia, and ice)

Hemodynamically unstable (expanding hematoma): treat with fluid resuscitation, reversal of coagulopathy, and transfusion of blood products.