Bilateral pleural effusion and interstitial lung disease as unusual manifestations of kikuchi-fujimoto disease: case report and literature review

BACKGROUND Kikuchi-Fujimoto's disease (KFD), also called histiocytic necrotizing lymphadenitis, is a rare, idiopathic and self-limited condition usually characterized by cervical lymphadenopathy and fever, most often affecting young patients. Aetiology is unknown. Differential diagnosis includes mainly malignant lymphoma, tuberculous lymphadenitis and systemic lupus erythematosus (SLE), so early diagnosis is crucial. Pleuropulmonary involvement due to isolated KFD has been seldom reported. CASE PRESENTATION a 32-year-old man, on treatment for iatrogenic hypothyroidism, was admitted due to high grade fever and painful cervical lymphadenopathies. KFD was diagnosed by lymph node biopsy. Some days after admission the patient got worse, he developed generalized lymphadenopathy, bilateral pleural effusion and interstitial lung disease. All of them resolved with prednisone and after two years of following up he remains asymptomatic and without evidence of any other associated disease. CONCLUSION Pleural effusion and interstitial lung disease are very uncommon manifestations of KFD. In our experience, treatment with oral prednisone was effective.