Histiocytic Necrotizing Lymphadenitis with Cupriavidus Pauculus Infection in a Patient with Graves Hyperthyroidism: A Case Report.

Histiocytic necrotizing lymphadenitis (HNL) is a self-limiting inflammatory disease presenting with fever and cervical lymphadenopathy. However, no case of HNL with confirmed bacterial infection has been reported. A 38-year-old man was admitted to our hospital owing to an intermittent fever from 8 days. He was diagnosed with Graves hyperthyroidism 3 months prior and began taking methimazole tablets orally. Physical examination revealed superficial lymphadenopathy and goiter of the thyroid (grade II). Blood routine showed a decrease in peripheral blood cells, including significant reduction in leukocytes and platelets. A bone marrow culture identified a very rare pathogen, Cupriavidus pauculus, but the antibiotic effect of meropenem was unsatisfactory. Biopsy of the left cervical lymph node revealed HNL, and the patient had no fever after using glucocorticoids. This case report indicates that clinicians should be aware of the coexistence of HNL and bacterial infections, especially in patients with Graves hyperthyroidism.