Question

A 52-year-old man with hypertension associated with recent unexplained weight loss presents with fever, malaise, and gradual onset of pain and weakness of his leg muscles for the past month. Physical examination reveals a mottled reticular pattern overlying portions of both calves and an area of ulceration with surrounding induration on the left lateral malleolus. Initial laboratory results reveal mild normochromic anemia, leukocytosis, and elevation of C-reactive protein, BUN, and creatinine. Which of the following is the most appropriate diagnostic evaluation to confirm the suspected diagnosis?(A) HLA-B27 typing(B) rheumatoid factor(C) MRI of sacroiliac joints(D) antinuclear antibodies test(E) tissue biopsy of area of induration

Answer 1

Answer: the correct answer is E. tissue biopsy of area of induration

Step-by-step explanation:

This patient most likely has polyarteritis nodosa (PN). A major obstacle in making the diagnosis is the absence of a disease-specific serological test. The diagnosis requires confirmation with either a tissue biopsy or angiogram. HLA-B27 antigens are not associated with the suspected diagnosis. While classic PN will have low titers of rheumatoid factor and antinuclear antibodies, both are nonspecific findings and will not confirm the diagnosis. An MRI of the sacroiliac joints is indicated in evaluation of the early stages of suspected ankylosing spondylitis and plays no role in the evaluation of PN.