History and clinical findings: A 26-year-old man had a prolonged fever, 10 kg weight loss and generalized lymphadenopathy, first diagnosed as a malignant lymphoma. On admission he was febrile and in a markedly reduced physical condition. Submandibular, angular, cubital and inguinal lymph nodes were slightly enlarged bilaterally.
Investigations: Serology and blood cultures were negative. Sonography and computed tomography showed enlarged lymph nodes in the neck, mediastinum, axillae, retroperitoneum and mesentery. Biopsies of lymph nodes and bone marrow revealed changes characteristic of Castleman's disease.
Treatment and course: Prednisone was administered, 20 mg daily for 20 days, the dose gradually reduced over 4 months. The fever ceased after 14 days and the patients's working capacity was fully restored after 7 weeks.
Conclusion: In a case of prolonged fever of unknown cause Castleman's disease should be included in the differential diagnosis. It at first consists of polyclonal lymphatic proliferation. But transformation to malignant lymphoma and systemic Kaposi's sarcoma have been described in the disease's generalized form.