General Surgery Board Review Sample Questions

The correct answer is B. Strong association with methysergide

Explanation: Retroperitoneal (RP) fibrosis is characterized by hyperproliferation of fibrous tissue. It is classified as either primary (Ormond’s disease), or secondary to an inciting inflammatory process, malignancy, or medication. Idiopathic/primary RP fibrosis is rare, affecting 0.5 per 100,000 annually. It is more common in men compared to women and affects patients in the fourth to sixth decades of life. The pathogenesis is unknown but speculated to be closely related to chronic periaortitis and associated with the HLA-DRB1-03 allele. This allele is also linked to systemic lupus erythematosus, type 1 diabetes mellitus, and myasthenia gravis. The fibrotic process begins in the RP just below the renal arteries and eventually expands, encasing ureters, inferior vena cava, aorta, mesenteric vessels, and sympathetic nerves. Bilateral involvement is noted in two-thirds of cases. Symptoms are generally vague, including dull abdominal or back pain, but can also present as leg swelling, claudication, oliguria, hematuria, and dysuria. Methysergide, a semisynthetic ergot alkaloid used in the treatment of a migraine headache, has been shown to play a causal role in many medication-induced cases of RP fibrosis. Other linked medications include beta blockers, hydralazine, alpha-methyl dopa, and entacapone, which is used in the treatment of Parkinson’s disease. In medication-induced RP fibrosis, discontinuation of the medication is curative. After imaging with CT, MRI, and/or ultrasound, biopsy should be performed if there is any consideration of malignancy in the differential. Any potential predisposing medications should be stopped, and high dose corticosteroids should be instituted. Other medications, such as cyclosporin, tamoxifen, and azathioprine have been used in those not responding to prednisone. Surgical therapy is reserved for biopsy (if cannot be performed with image-guided techniques), or to address complications of the disease, such as ureterolysis of encased ureters, or vascular bypass, though the endovascular approach is preferred in most situations. 5-year survival is 90-100%.