Usefulness of Fluorodeoxyglucose-positron emission tomography/computed tomography (PDG-PET/CT) scan on diagnosis of kikuchi disease

Kikuchi Disease (KD) or histiocytic necrotizing lymphadentitis is a rare cause of lymphadenopathy. The aim of this study was to analyze the diagnostic pathway of KD and clarify the usefulness of Fluorodeoxyglucose-positron emission tomography/computed tomography (F-18-FDG PET/CT). Twenty-four patients who had fever with unknown origin and lymphadenopathy were prospectively recruited. F-18-FDG PET/CT scan was performed. Clinical manifestation, laboratory examination, bone marrow and biopsy of lymph node were recorded. PET/CT scan revealed diverse FDG uptake in the organs and lymph nodes in all the 24 patients. The pathological results identified lymphoma in five patients, KD in five patients, plasma cell dyscrasia in one patient, and cholangiocarcinoma in one patient. Six patients were diagnosed with autoimmune disease. One patient was confirmed with tuberculosis. Another 5 patients didn't have a definite diagnosis. In 5 KD patients, cervical and axillary lymph nodes were the most common affected lymph nodes with obvious elevated uptake of F-18-FDG. All the affected lymph nodes were indicated by PET/CT for their location and sizes, which facilitates lymph node biopsy. All the KD patients recovered well and remained good situation in six months after diagnosis after the treatment of NSAIDs or glucocorticoid. Lymphoma, cancer, KD and infection should be considered for patients with fever, multiple enlarged lymph nodes with high FDG uptake. F-18-FDG PET/CT could not discriminate KD and lymphoma but is helpful to differentiate with autoimmune diseases and other inflammation.