POEMS syndrome with myocardial infarction: observations concerning pathogenesis and review of the literature.

A 27-year-old white man with no significant risk factors for coronary artery disease presented with a 9-month history of progressive impotence, gynecomastia, lower extremity paresthesias, and extensive myocardial infarction and subsequently developed ulcerative proctitis. A diagnosis of POEMS syndrome was made based on the clinical presentation; additional physical findings of papilledema, clubbing, and hyperpigmentation; and laboratory findings of an immunoglobulin G M component of the lambda subtype, elevated cerebrospinal fluid protein, and typical sclerotic bone lesions. Abnormal in vitro binding of the patient's serum immunoglobulin to testicular tissue was also seen. Cardiac catheterization showed evidence of diffuse coronary artery narrowing and left ventricular wall motion abnormalities. Diffuse coronary involvement and ulcerative proctitis have not been previously described in POEMS syndrome. It is hypothesized that an abnormal immunoglobin (or fragment) is responsible for both findings. Furthermore, the detection of antitesticular autoantibodies suggests the possibility of an interaction between the antibody and Leydig cells, leading to an alteration in the synthesis and release of sex steroids and thereby explaining the gonadal failure seen in this syndrome. Long-term glucocorticoid therapy for the past 5 years has resulted in marked subjective and objective improvement.