Kikuchi-Fujimoto Disease: A Rare Cause of Pyrexia of Unknown Origin and Cervical Lymphadenopathy

Abstract

Kikuchi-Fujimoto disease (KFD) is a benign disorder characterized by regional cervical lymphadenopathy with tenderness. Associated symptoms of KFD include low-grade fever, night sweats, weight loss, nausea, and sore throat. The disease is a sporadic disease known to have a worldwide distribution with a higher prevalence among Asian communities. Although the clinical and histopathological features point to a viral etiology, this hypothesis has not been proven yet. Generally, the diagnosis is made based on a lymph node excisional biopsy. Its recognition is crucial mainly because this disease can be mistaken for other disorders, including systemic lupus erythematosus or malignant lymphoma. Supportive treatment includes antipyretics, non-steroidal anti-inflammatory drugs, and corticosteroids. Spontaneous recovery occurs within a few weeks. Patients should be followed up for years to survey because there is a possibility of developing systemic lupus erythematosus. In this article, we report the case of a patient who presented with a fever of unknown origin and lymphadenopathy, treated with multiple antibiotic courses with no improvement. Workup including computed tomography of the neck with contrast and lymph node biopsy confirmed the diagnosis of KFD. His condition improved after administering analgesics and multivitamins, and he was advised to rest at home.

Keywords: cervical lymphadenopathy; kikuchi-fujimoto disease; necrotizing granulomatous lymphadenitis; puo (pyrexia of unknown origin); unexplained fever.

Figure 1. Grayscale (left) and color Doppler (right) ultrasound of the left supraclavicular region shows enlarged round lymph nodes with preserved fatty hilum and normal vascularity, measuring 9.5 mm in the short axis.

Figure 2. Axial (A) and coronal (B) computed tomography of the neck with contrast show left supraclavicular enlarged lymph nodes but no necrosis or calcification (orange arrow). Multiple bilateral reactive deep cervical lymph nodes can be seen (green arrow).

Figure 3. Light microscopic examination showing a lymph node with patchy necrotic areas (arrowheads) (hematoxylin and eosin, ×40).

Figure 4. Light microscopic examination showing the eosinophilic necrotic area with karyorrhectic debris on the left side surrounded by sheets of plasmacytoid histiocytes and lymphocytes on the right side (hematoxylin and eosin, ×400).