Kikuchi-Fujimoto disease masquerading as dysphagia with an isolated pulmonary nodule: a clinical conundrum

Kikuchi-Fujimoto Disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare disease predominantly seen in young Asian women. Although the exact cause is unknown but several autoimmune and infectious etiologies have been postulated. It is characterized by cervical lymphadenopathy, low-grade fever, night sweats and leukopenia. Clinically, it mimics several diseases, leading to misdiagnosis and inappropriate treatment. Diagnosis is confirmed by histopathological examination of the lymph node. A 40 year old male with no comorbidities presented with complaints of multiple neck swellings, dysphagia and odynophagia for both solids and liquids for two months, associated with low-grade fever and significant weight loss. On examination, multiple bilateral cervical lymph nodes were palpable. Hematological study showed raised ESR (Erythrocyte Sedimentation Rate) and CRP (C-Reactive Protein). Ultrasonography and contrast-enhanced CT (CECT) of the neck showed multiple bilateral cervical and preauricular lymphadenopathy. CECT of the chest revealed Hilar and Mediastinal lymphadenopathy with calcifications and a solitary pleural-based solid pulmonary nodule with smooth margins and soft tissue density in the anterior segment of the lower lobe of the right lung. Excision biopsy and histopathological examination confirmed the diagnosis of Kikuchi-Fujimoto disease. The patient completely recovered with a short course of oral methylprednisolone (tapered dose). Atypical presentations of Kikuchi-Fujimoto disease pose a diagnostic challenge and may lead to inappropriate treatment and complications. It should be considered in patients presenting with persistent low-grade fever, cervical lymphadenopathy and leukopenia. In addition to its classical features, KFD may be associated with prominent upper aerodigestive symptoms and a solitary pulmonary nodule; awareness of such uncommon presentations may aid clinicians to consider KFD in the differential diagnosis. A multidisciplinary approach is crucial for accurate diagnosis and appropriate management, particularly in cases with atypical clinical or radiological findings.