The Role of PET/CT in the Diagnosis of Kikuchi-Fujimoto Disease: A Case Series and Review of the Literature

Abstract

Introduction: Kikuchi-Fujimoto disease (KFD), also known as Kikuchi's disease or histiocytic necrotizing lymphadenitis, is a self-limiting case of non-cancerous lymphadenopathy. Although previous reports have demonstrated its physical findings and traditional imaging characteristics, few studies mentioned the application of 18 fluorodeoxyglucose positron emission tomography-computed tomography ( 18 F-FDG PET/CT) imaging in the diagnosis and follow-up of this disease. Here, we present three cases of KFD, describe the findings from PET/CT images and review relevant literature to improve the diagnosis of this rare disease.

“String of pearls sign” on FDG PET imaging in two patients with PUO of diverse etiologies and rare associations

“…Reports show KFD's predilection for cervical lymphadenopathy, small-or medium-sized similar to our case. Nodal involvement is usually discrete and involves levels II, III, and IV with CT findings of low attenuation nodes [6]. In our study, we found bilateral involvement of discrete supradiaphragmatic (cervical, axillary, and deep pectoral) along with fewer infra diaphragmatic (periportal, portocaval and inguinal) nodal involvement.…”

“…Thus, "string of pearls sign" is a non-specific PET finding and can be present in nodal disease of diverse etiologies Anatomic and functional imaging procedures like CT and PET are not diagnostic for KFD. The affected lymph nodes in KFD appear enlarged, lose their normal shape, and acquire an abnormal round shape with associated FDG avidity indicating infection, inflammation, or a neoplastic underlying pathology [6]. The nodes may show unilateral or bilateral involvement.…”

“…One of the studies reported extensive discrete and matted lymph nodes [7]. Gold standard for the diagnosis of KFD is biopsy of the affected lymph node [6]. Treatment is supportive with nonsteroidal anti-inflammatory drugs and corticosteroids.…”