Idiopathic infarction of intraabdominal lymph nodes. A cause of fever of unknown origin.

Infarcted peribiliary lymph nodes were found at laparotomy in a 56-year-old man who had a fever of unknown origin and transient abdominal pain. Despite thorough clinical and laboratory investigation, a cause was not demonstrated. A review of the reported cases of idiopathic or spontaneous lymph node infarction revealed a clinical presentation characterized by the sudden appearance of a painful mass, often associated with otherwise unexplained fever. Most clinical laboratory test results were negative. Although the pathogenesis is not known, histologic changes in involved lymph nodes are indistinguishable from those produced experimentally by occlusion of the vascular supply of lymph nodes. The histologic differential diagnosis includes lymphoma, metastatic carcinoma, vasculitis, and infection.