A Young Woman with Worsening Abdominal Pain

Differential Diagnosis

• Constipation
• Renal colic
• Staghorn calculus
• Urolithiasis

Diagnosis

The patient was diagnosed with constipation and left staghorn calculus. The x-ray shows the obvious diagnosis of constipation as well as the incidental finding of a large calcification shaped like the left renal collecting system.

Learnings/What to Look for

• Staghorn calculi are the result of recurrent urinary tract infections and thus occur more in women and patients with renal collecting system anomalies, urinary reflux, spinal cord injuries/neurogenic bladder, and ideal conduits
• Most are symptomatic, presenting with fever, hematuria, and flank pain and occasionally sepsis
• Staghorn calculi are composed of struvite (magnesium ammonium phosphate) and usually occur with urease-producing bacterial infections (Proteus, Klebsiella, Pseudomonas, and Enterobacter)
• Remember to review the entire radiograph rather than simply the structures of concern, as significant incidental findings can be missed

Pearls for Urgent Care Management and Considerations for Transfer

• Staghorn calculi are treated surgically. Untreated, staghorn calculi can cause chronic infection and may progress to xanthogranulomatous pyelonephritis
• Urgent referral to a urologist is warranted for stable patients. Patients with fever should be referred to an emergency department immediately

 Acknowledgment: Images and case provided by Experity Teleradiology (www.experityhealth.com/teleradiology).