18F-FDG PET/CT findings in Kikuchi disease

1377 Objectives We investigated the manifestation of F-18 FDG PET/CT in Kikuchi disease. Methods We retrospectively searched medical records of pathologically proven Kikuchi disease patients from Dec. 2003 to Aug. 2010. Of these patients, only 9 patients (6 males and 3 females) underwent PET/CT are enrolled. Five patients are an age group under 20 years, and 4 patients are over 20 years (ranging from 3 to 50 years). PET/CT findings were categorized as bilateral cervical, axillae, mediastinum, abdomen & retroperitoneum according to the lymph nodes involvement sites. The maximal standardized uptake values (SUVmax) and the size of lymph nodes were measured. Results Symptom that presented by all patients was fever, and only 3 patients suffered from cervical lymph nodes swelling. Serum LDH and ESR were elevated in most of patients. FDG activity is appeared at body regions in following order; neck (all patients), axilla (6 patients), abdomen & retroperitoneum (5 patients), and mediastinum (3 patients). The SUVmax of affected lymph nodes range 0.8-16.2 (mean 5.6±4.8) in all body regions, 0.8-16.2 in neck, 0.8-7.5 in axilla, 1.9-6.9 in mediastinum, and 1.8-12.0 in abdomen & retroperitneum. Size of all affected lymph nodes is less than 30 mm in diameter. In all patients but one, involved lymph nodes are showing homogeneous pattern on non-enhanced CT images of PET/CT scan. Conclusions Kikuchi disease involves multiple lymph nodes of various body regions, and most commonly involved site is neck. Our study shows similar result that all neck regions are involved. But, the activity of involved lymph nodes shows varying range. In the majority of lymph nodes show homogeneous pattern in non-enhanced CT images. These non-specific findings are represented in a few diseases that involve multiple lymph nodes such as malignant lymphoma or tuberculosis lymphadenitis. So, PET/CT is ancillary modality that evaluates disease extent and decides biopsy site in Kikuchi disease