A case of Schnitzler's syndrome with nodular regenerative hyperplasia of the liver.

Schnitzler's syndrome is a rare condition of urticaria, macroglobulinemia, and sclerotic bone lesions. We report a case in a 70-year-old man in whom inflammatory polyarthralgia was followed by a nonpruritic urticarial eruption with a moderate decline in general health. Laboratory tests showed inflammation and a modest isolated peak of monoclonal IgM kappa. There was no evidence of Waldenström macroglobulinemia. Schnitzler's syndrome was considered. However, an ultrasound scan of the abdomen done because of mild gamma-glutamyl-transferase elevation disclosed multiple hepatic lesions. The liver histology showed incipient nodular regenerative hyperplasia. Only about 30 cases of Schnitzler's syndrome have been reported since the seminal description in 1972. Hepatic involvement was a common but nonspecific finding, and we found no cases with nodular regenerative hyperplasia. However, this abnormality is often found in patients with autoimmune or hematological disorders. The pathogenesis of Schnitzler's syndrome remains unknown, but the possibility of progression to a hematological malignancy requires prolonged follow-up.