Fine Needle Aspiration Cytology of Kikuchi's Lymphadenitis: with Emphasis on Differential Diagnosis with Tuberculosis

The fine-needle aspiration cytology and clinical findings of Kikuchi-Fujimoto disease in pediatric patients: a retrospective clinical study

BACKGROUND

Histological evaluation of lymph node is crucial for the definitive diagnosis of Kikuchi-Fujimoto disease (KFD). However, lymph node biopsy under local anesthesia is often difficult in pediatric patients.

OBJECTIVES

We evaluated cytological findings for pediatric patients with prolonged cervical lymphadenitis clinically suggestive of KFD and investigated the clinical characteristics of patients diagnosed with KFD by fine-needle aspiration cytology (FNAC).

METHODS

This retrospective clinical study included 58 Japanese pediatric patients with cervical lymphadenitis who underwent FNAC.

RESULTS

Cytological diagnosis was KFD for 22 and suspicion of KFD for 11 patients. The remaining 25 patients were diagnosed with non-specific lymphadenitis (NSL). Tenderness was independently associated with a higher frequency of both KFD in narrow and broad senses, compared with NSL (p = .009; p = .038). The percentage of patients who underwent FNAC within 28 days from symptom onset tended to be higher among patients with KFD in a narrow sense than those with NSL (p = .052).

CONCLUSION

This study indicated that the period from symptom onset to FNAC (<28 days) and the symptom of tenderness were associated with the cytological diagnosis of KFD.

Kikuchi-Fujimoto disease in the Eastern Mediterranean zone

Kikuchi–Fujimoto disease (KFD) is a rare benign and self-limiting syndrome. We aim to review cases of KFD at our institution as a rare illness in the Arab ethnic descent and to analyse reports from most countries in the East Mediterranean zone. This is a retrospective study in which the histopathology database was searched for the diagnosis of KFD. A full review of KFD patients’ medical records was done. Data regarding demographic features, clinical presentation, laboratory findings, comorbidities, and management protocols were obtained. Published KFD cases from east Mediterranean countries were discussed and compared to other parts of the world. Out of 1968 lymph node biopsies studied, 11 (0.6%) cases of KFD were identified. The mean age of patients with KFD was 32 years (4–59). 73% (8/11) were females. The disease was self-limiting in 5 patients (45%); corticosteroid therapy was needed in 4 patients (34%). One patient was treated with methotrexate and one with antibiotics. One patient died as a consequence of lymphoma. Jordanians and Mediterranean populations, especially those of Arab ethnic background, seem to have low rates of KFD. The genetic susceptibility theory may help to explain the significantly higher disease prevalence among East Asians. Early diagnosis of KFD—although challenging—is essential to reduce the morbidity related to this illness.

Identification of Torque Teno Virus/Torque Teno-Like Minivirus in the Cervical Lymph Nodes of Kikuchi-Fujimoto Lymphadenitis Patients (Histiocytic Necrotizing Lymphadenitis): A Possible Key to Idiopathic Disease

Kikuchi-Fujimoto disease (KFD) is rare, and many infectious agents have been suspected for its etiology. This report presents an interesting case of KFD found with torque teno virus/torque teno minivirus (TTV/TTMV), which closely resembles the circovirus that causes necrotizing lymphadenitis in pigs. Three Korean patients showed several enlarged lymph nodes in their neck. Quantitative polymerase chain reaction (qPCR) and subsequent DNA sequencing for TTV/TTMV using formalin-fixed paraffin-embedded tissue were performed. Histologic examination demonstrated typical features of KFD. qPCR showed successful amplification of TTV/TTMV, and DNA sequencing confirmed the results. It is the first report of TTV/TTMV presence in three patients with KFD.

Causative agents of Kikuchi-Fujimoto disease (histiocytic necrotizing lymphadenitis): a meta-analysis

OBJECTIVE

Kikuchi-Fujimoto disease (KFD) is a self-limiting disorder characterized by histiocytic necrotizing lymphadenitis in the cervical lymph nodes of young women. Although an infectious etiology has been postulated, a definitive causative agent has not been identified. The few dozens of published studies are limited by small sample size and poorly structured study designs. The purpose of this study is to evaluate the association of each infectious agent to KFD that has been studied.

METHODS

We performed metaanalysis using major electronic database (MEDLINE (PubMed), Cochrane library, Embase, Web of Science, NML gateway, LILACS, and Google Scholar). Cross-sectional studies on the positivity of each agent in clinicopathologically diagnosed KFD and normal controls by polymerase chain reaction (PCR) or in situ hybridization (ISH) were carefully retrieved. The included infectious agents were herpes simplex virus (HSV) type 1, 2, varicella-zoster virus, cytomegalovirus, Epstein-Barr virus (EBV), human herpes virus (HHV) 6, 7, 8, parvovirus B19, human papilloma virus, hepatitis B virus, human T-lymphotropic virus 1, Brucella, and Bartonella henselae.

RESULTS

After an exclusion process of 2491 studies, five, two, four, two, two, and three studies on EBV-PCR, EBV-ISH, HHV6-PCR, HHV8-PCR, parvovirus B19-PCR and HHV7-PCR, respectively, were suitable for quantitative meta-analysis.

CONCLUSION

The most suspected pathogen, EBV was not associated to KFD than normal controls (odds ratio=0.28, p=0.005), while the HHV8 positivity was more likely to be associated (odds ratio=8.24, p=0.003) although it still needs further verification. None of other viruses was associated to KFD although the results are limited by small sample size. More studies with large sample size and strict sample selection criteria are necessary in future.