Kikuchi's disease (histiocytic necrotizing lymphadenitis). A clinicopathologic study of 79 cases with an analysis of histologic subtypes, immunohistology, and DNA ploidy

Kikuchi-Fujimoto Disease Associated With Mycoplasma Pneumoniae Infection

Kikuchi-Fujimoto disease (KFD) is a self-limited disease that is more common in young Asian women. Typical presentations included fever and cervical lymphadenopathy. The etiology of KFD is unknown, and diagnosis is based mainly on lymph node biopsy. KFD has been reported to be associated with Mycoplasma pneumoniae infection. However, the role of antibiotic treatment is unclear. We reported 2 cases of KFD associated with Mycoplasma pneumoniae infection and were successfully treated with a macrolide.

Clinical features of histiocytic necrotizing lymphadenitis in children

Due to its nonspecific clinical characteristics, histiocytic necrotizing lymphadenitis (HNL) is often misdiagnosed as a suppurative cervical lymphadenitis and lymphoma. Thus, this study aimed to investigate the clinical characteristics of HNL in pediatric patients. We retrospectively identified 61 patients with histopathologically confirmed HNL. Clinical and laboratory data, including age, sex, clinical manifestations, laboratory investigations, histological discoveries, treatment, and outcomes, were collected from the medical records to determine associations with extracervical lymph node (LN) involvement. The mean age of patients was 9.7 ± 2.8 years (range, 1.5-14.0 years), and the male-to-female ratio was 2.2:1. The most common systemic symptom was fever in all patients. The median pre-admission and total durations of fever were 13.0 (interquartile range [IQR]: 9.0-22.5 days) and 22.0 days (IQR: 17.0-33.0 days), respectively. Patients with temporary fever (< 2 weeks) had a higher peak temperature and were more likely to undergo LN biopsy after admission than those with a prolonged fever (≥ 2 weeks). Multivariate analysis revealed that peak temperature ≥ 40 °C was significantly associated with a longer fever duration (P = 0.023). Laboratory values showed leukopenia (68.9%), which presented more frequently in solitary cervical LNs than in extracervical LNs (82.4% vs. 52.9%, p = 0.027) in patients with prolonged fever.

CONCLUSIONS

HNL is often misdiagnosed in older children with persistent fever and lymphadenopathy, leading to unnecessary diagnostic tests and evaluations, inappropriate antibiotic administration, and mismanagement. A multidisciplinary team, including primary care providers, rheumatologists, and pathologists, can improve patient outcomes by increasing their awareness of this rare condition.

WHAT IS KNOWN

• Histiocytic necrotizing lymphadenitis (HNL) is characterized by fever, leukopenia, and neck lymphadenopathy with unknown etiology. • The lack of neutrophils or eosinophils in the histology, immunohistochemistry results help distinguish HNL from infectious causes. Although HNL is a self-limiting disease, antibiotics and steroid treatments were used inappropriately.

WHAT IS NEW

• A fever peak ≥ 40 °C was associated with a longer fever duration in HNL patients. Leukopenia presented more frequently in solitary cervical lymph node (LNs) than in extracervical LNs inpatients with prolonged fever. • Steroids are not recommended as a routine treatment, however, in some severe or relapsing cases with persistent symptoms, prednisolone (5 mg twice a day for 2 days) or other steroids (an equivalent dose of prednisolone) responded favorably.

Reactive Lymphadenopathy in the Pediatric Population with a Focus on Potential Mimics of Lymphoma

Benign lymphadenopathy is common in the pediatric population and may be clinically striking. As in adults, lymph node evaluation in pediatric patients requires careful morphologic and immunohistochemical assessment and clinical contextualization of the findings. It is important for the pathologist to be familiar with benign and reactive conditions that may mimic malignancy. This review presents non-neoplastic or indolent processes or patterns of lymphoid hyperplasia that may be confused with or raise the differential of lymphoma, with a focus on those more commonly encountered in the pediatric/adolescent population.

Kikuchi-Fujimoto Disease: A Case of Febrile Cervical Lymphadenopathy With Hematological Abnormalities

Kikuchi-Fujimoto disease (KFD), or histiocytic necrotizing lymphadenitis, is a benign but rare disorder associated with febrile cervical lymphadenopathy in young adults. Here, we discuss a case of a young female patient presenting with left tender cervical lymphadenopathy that progressed bilaterally with a fever of unknown origin. Laboratory parameters showed persistent leukopenia, especially neutropenia, which fluctuated with the degree of symptom severity. Two months were taken to confirm the diagnosis of KFD based on the histological interpretation of the lymph node biopsy. Supportive management with analgesics and paracetamol formed the main treatment. This case highlights the challenges and importance of diagnosing KFD to exclude other serious conditions such as lymphoma, tuberculosis, or lupus lymphadenitis that share similar clinical manifestations as KFD.

Kikuchi-Fujimoto Disease With Systemic Lupus Erythematosus and Systemic Sclerosis Overlap: A Unique Clinical Presentation

Kikuchi-Fujimoto Disease (KFD), or histiocytic necrotizing lymphadenitis (HNL), is a rare self-limiting disorder presenting with fever and swollen lymph nodes. It is characterized by the focal proliferation of reticular cells, the presence of nuclear debris, and histiocytes. In advanced cases, it can present with hepato-splenomegaly and generalized lymphadenopathy. Historically, it has been associated with viral infections, as it frequently was found to be associated with upper respiratory symptoms. Alternative explanations include the immune response of T-cells leading to alteration in CD8-positive T-cell-mediated cell apoptosis. It is also speculated that KFD can be associated with rheumatological autoimmune diseases. We present a case of a 21-year-old African American female with a known diagnosis of systemic lupus erythematosus (SLE)-systemic sclerosis (SS) overlap presented with febrile lymphadenopathy and was diagnosed to have HNL on histological exam of lymph node biopsy.

Kikuchi-Fujimoto Disease Following COVID-19 Vaccination: Experience at a Population-Based Referral Center

OBJECTIVES

Multiple case reports describe Kikuchi-Fujimoto disease (KFD) following COVID-19 vaccination, but the true nature of this phenomenon is unknown. The purpose of this study was to further assess the relationship between KFD and COVID-19 vaccination at the population level.

METHODS

Confirmed KFD cases from January 2018 to April 2022 were identified from provincial pathology archives and analyzed in the context of vaccination statistics from public health resources.

RESULTS

Our statistical models provide evidence of a temporal association between KFD and both antecedent COVID-19 vaccine administration as well as age-stratified vaccination rates. Eight new cases of plausible COVID-19 vaccine-associated KFD are presented, collectively exhibiting clinical and pathologic features that overlap substantially with those of idiopathic KFD.

CONCLUSIONS

Our findings indicate that KFD is observed in association with COVID-19 vaccination and suggest that mechanistic studies are warranted.

A retrospective study of 134 patients with cervical region Kikuchi-Fujimoto disease

Background

To explore the clinical and laboratory features, therapy and prognosis of Kikuchi-Fujimoto disease (KFD) in the cervical region.

Methods

We retrospectively reviewed the medical records of 134 patients who were diagnosed and treated with KFD from January 2000 to May 2022 in Fujian Medical University Union Hospital (Fujian, China). Their clinical characteristics, affected lymph node size, imaging examinations, and laboratory study results were analyzed.

Results

The mean patient age was 24.9 years, and the male-female ratio was 1:1.73. Fever (55.2%, n = 74) was the most common clinical manifestation. Leukopenia (49.3%) was the commonest reported laboratory abnormality. A majority (65.7%) of the 134 patients presented with bilateral nodal involvement.

Conclusion

KFD should be considered as a possible diagnosis in a female patient under the age of 30 presenting with cervical lymphadenopathy, fever, leukopenia, and elevated LDH.

Level of Evidence

4.

Clonal T-cell proliferations occasionally occur in Kikuchi-Fujimoto disease

Kikuchi-Fujimoto disease (KFD) is a benign self-limiting disorder that frequently leads to swelling of cervical lymph nodes in young women. It has a characteristic histologic appearance with sharply demarcated foci containing apoptotic debris, histiocytes, and proliferating large T-cells. Since in the past years, core needle biopsies have been increasingly used for diagnostic work-up, a small biopsy of the pathognomonic proliferating T-cell foci may lead to misinterpretation as a large T-cell neoplasia. The aim of the present study therefore was to analyze how frequently clonal T-cell receptor (TCR) amplificates may be obtained in KFD using a commonly used TCR gamma rearrangement clonality assay. In 88 KFD cases, TCR gamma clonality assays could be successfully applied. Clonal peaks of TCR gamma in front of a polyclonal background were observed in 15 cases (18%). The investigated clinical parameters (age, gender, extent of infiltration of the lymph node, percentage of proliferative compartment) did not differ between patients with detectable TCR gamma clones from those patients who had polyclonal TCR gamma results. Our study therefore demonstrates that clonal TCR gamma amplificates may be obtained in any type of KFD and that an over-interpretation of clonal T-cell proliferates in diagnostically equivocal material should be avoided.

Diagnostic Dilemma in a Case of Necrotizing Lymphadenitis With Macrophage Activation Syndrome

Necrotizing lymphadenitis is a histological diagnosis that can arise from various conditions, including lupus lymphadenitis (LL), Kikuchi disease (KD), and infectious causes. Distinguishing between Kikuchi disease and lupus lymphadenitis can be challenging in clinical practice. In this report, we present the clinical scenario of a young female patient with lymphadenopathy and elucidate the process through which we ultimately arrived at a diagnosis of systemic lupus erythematosus (SLE) with macrophage activation syndrome. This case underscores the significance of recognizing Kikuchi disease as a condition that can mimic lupus and sheds light on the distinguishing features of necrotizing lymphadenitis, with a particular focus on Kikuchi disease and lupus lymphadenitis.

Kikuchi-Fujimoto disease: A comprehensive review

Kikuchi-Fujimoto disease, a rare form of necrotizing lymphadenitis, is an uncommon, benign, self-limiting disorder of obscure etiology. It affects mostly young adults of both genders. Clinically, it presents with fever and lymphadenopathy of a firm to rubbery consistency frequently involving cervical lymph nodes while weight loss, splenomegaly, leucopenia, and elevated erythrocyte sedimentation rate feature in severely affected patients. Cutaneous involvement occurs in about 30%-40% of cases as facial erythema and nonspecific erythematous papules, plaques, acneiform or morbilliform lesions of great histologic heterogeneity. Both Kikuchi-Fujimoto disease and systemic lupus erythematosus share an obscure and complex relationship as systemic lupus erythematosus may occasionally precede, develop subsequently, or sometimes be associated concurrently with Kikuchi-Fujimoto disease. It is often mistaken for non-Hodgkin lymphoma while lupus lymphadenitis, cat-scratch disease, Sweet’s syndrome, Still’s disease, drug eruptions, infectious mononucleosis, and viral or tubercular lymphadenitis are other common differentials. Fine needle aspiration cytology mostly has features of nonspecific reactive lymphadenitis and immunohistochemistry studies usually show variable features of uncertain diagnostic value. Since its diagnosis is exclusively from histopathology, it needs to be evaluated more carefully; an early lymph node biopsy will obviate the need for unnecessary investigations and therapeutic trials. Its treatment with systemic corticosteroids, hydroxychloroquine, or antimicrobial agents mostly remains empirical. The article reviews clinicoepidemiological, diagnostic, and management aspects of KFD from the perspective of practicing clinicians.

Kikuchi-Fujimoto-like lymphadenopathy following COVID-19 vaccine: diagnosis and management

A woman in her mid 40s presented for breast imaging after 1 week of painful and enlarged right axillary lymphadenopathy. She denied history of fever, weight loss, night sweats fatigue, cat scratch or other trauma. She received the second dose of Pfizer COVID-19 vaccine 3 months previously on the contralateral arm. A mammogram demonstrated a single, asymmetric, large and dense right axillary lymph node. Ultrasound confirmed a 2.5 cm lymph node with cortical thickening of 0.6 cm. Ultrasound-guided core biopsy showed necrotising lymphadenitis with associated aggregates of histiocytes and plasmacytoid dendritic cells. Potential causes of necrotising adenitis including Bartonella, tuberculosis, Epstein-Barr Virus, herpes simplex virus, systemic lupus erythematosus and lymphoma were excluded. In the absence of any identifiable infectious or autoimmune causes, and given the temporal relatedness with vaccine administration, it was determined that the Kikuchi-Fujimoto-like necrotising lymphadenitis was likely secondary to the COVID-19 vaccine. To date, there has been no casual association made between the COVID-19 vaccine and KFD necrotising lymphadenitis.

A Malignant Mimicker: Features of Kikuchi-Fujimoto Disease in the Pediatric Population

BACKGROUND

Kikuchi-Fujimoto disease (KFD) is a rare, benign, and self-limited disease that presents with cervical lymphadenopathy and systemic symptoms. Histologic evaluation is often necessary to differentiate KFD from other entities.

METHODS

Electronic medical records and diagnostic material were reviewed for 14 children diagnosed with KFD and 6 children diagnosed with infectious mononucleosis (IM) from 2013-2021. Four cases of KFD were further characterized using targeted DNA-based next-generation sequencing.

RESULTS

Systemic symptoms were present in 86% (n = 12/14) of KFD patients, the most common being fever. Laboratory values worrisome for malignancy included cytopenia(s) (n = 9/12), elevated ESR and/or CRP (n = 9/12), elevated ferritin (n = 7/7), and elevated LDH (n = 7/10). Histologically, lymph nodes showed characteristic necrotic foci without neutrophils surrounded by MPO+ "crescentic" histiocytes. Immunoblasts and CD123+ plasmacytoid dendritic cells (pDCs) were also increased surrounding the necrosis. IM lymph nodes showed similar features when necrosis was present but increases in pDCs were patchy and rare neutrophils were seen in the necrotic foci. Molecular analysis of 4 KFD cases did not identify pathogenic variants.

CONCLUSION

While the signs/symptoms of KFD are worrisome, there are pathologic features that help differentiate it from potential mimics. We did not identify characteristic molecular features to aid in the work-up of these cases.

Kikuchi-Fujimoto Disease: A Differential for When It is Not Systemic Lupus Erythematosus

Kikuchi-Fujimoto disease (KFD) is a rare and benign disease process that is characterized by fever and lymphadenopathy that was first described in young Japanese women in the early 1970s. Knowledge of KFD is important as it can often mimic other causes of lymphadenopathy including systemic lupus erythematosus (SLE) or malignancies, and this can lead to invasive diagnostic testing and even treatments that can be avoided. The etiology and exact mechanism by which KFD develops is not fully understood at this time, but is thought to be an immune response of T cells and histiocytes to viral or bacterial infections. We present a 35-year-old African-American woman who was referred to the rheumatology clinic by our colleagues in the breast clinic with new onset right axillary lymphadenopathy and abnormal serologic testing with the suspicion of SLE after a malignancy had been ruled out.

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.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Hematolymphoid Proliferations and Neoplasia

In the 5th edition of the World Health Organization (WHO) Classification of Head and Neck Tumours, the discussion of hematolymphoid proliferations is substantially reorganized and expanded in comparison to the prior edition. The 5th edition includes, in addition to hematolymphoid neoplasms, reactive lymphoid proliferations. Much more information on hematolymphoid proliferations that commonly affect cervical lymph nodes, in addition to those affecting extranodal sites in the head and neck, is included. For the first time, there are dedicated sections on multiple entities, including recently described lymphoproliferative disorders such as EBV+ mucocutaneous ulcer and pediatric-type follicular lymphoma, and several types of histiocytic neoplasms. Tremendous advances have been made in understanding the genetic features that underlie the pathogenesis of hematolymphoid neoplasms, and these have been incorporated into the WHO Classification.

Kikuchi-Fujimoto Disease Complicated by Rheumatoid Arthritis, Type 1 Diabetes Mellitus, and Hypothyroidism

Kikuchi-Fujimoto disease (KFD) is a rare, benign, self-limited syndrome characterized by tender lymphadenopathy and low-grade fever. It may also present with rash, arthritis, fatigue, and splenomegaly. Data on the disease is limited, and its etiology remains largely unknown.

Here, we present the case of a 30-year-old female with a medical history of rheumatoid arthritis (RA), previously treated with etanercept, type 1 diabetes mellitus (DM-1), and Hashimoto’s hypothyroidism; she was brought in to an emergency department (ED) in Houston after a generalized tonic-clonic seizure and loss of consciousness. She was hypoglycemic, which was thought to have caused her DM-1 and seizure. CT scan of her chest showed multiple enlarged lymph nodes throughout the neck, superior mediastinum, and axilla, along with interstitial edema and bilateral pleural effusions. She was treated with dextrose drip and regained her consciousness. However, she had persistent pancytopenia, low-grade fever, and tender axillary lymphadenopathy. Infectious workup for tuberculosis (TB), human immunodeficiency virus (HIV), herpes simplex virus (HSV), Epstein-Barr virus (EBV), and parvovirus B-19 were negative. Her bone marrow biopsy revealed iron-deficiency anemia, while excisional axillary lymph node biopsy showed extensive necrosis consistent with KFD. She was treated with supportive care. Her neutrophilic fever resolved, and she was discharged home after 48-hours of remaining afebrile. Six months after her hospitalization, the patient remained well, and her complete blood count showed no abnormalities.

Due to the non-specific clinical features and laboratory findings of KFD, it is commonly misdiagnosed as infectious, autoimmune, or malignant lymphadenitis, leading to excessive diagnostic tests and unnecessary treatments. Physicians need to be cognizant of KFD and consider it in young patients presenting with tender lymphadenopathy, low-grade fevers, and leukopenia. To our best knowledge, this is the first reported case of a patient with concurrent RA, Hashimoto’s hypothyroidism, and KFD. This report elucidates the autoimmune nature of KFD and its association with other autoimmune diseases.

Analysis of the clinical manifestations and 18F-FDG PET-CT findings in 40 patients with histiocytic necrotizing lymphadenitis

Histiocytic necrotizing lymphadenitis (HNL) is a rare, benign, and self-limiting inflammatory disease that mainly involves the lymph nodes. There is a lack of large sample studies concerning the clinical manifestations and imaging features of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) of HNL.The clinical symptoms, laboratory examination results, 18F-FDG PET/CT imaging features, and treatment outcome were investigated in this retrospective study.A total of 40 HNL patients were recruited. The onset age was between 14 and 65 years, with a median of 25 years. The white blood cell count was 3.9 (2.9, 7.1) × 109/L, C-reactive protein level was 20.2 (6.6, 63.8) mg/L, erythrocyte sedimentation rate was 29.0 (18.0,45.0) mm/h, and ferritin was 616.5 (205.6, 2118.1) ng/mL. An abnormal liver function was observed in 23 patients. 18F-FDG PET-CT showed that an abnormal lymph node metabolism was observed in 38 patients, among which the highest 18F-FDG maximal standard uptake value (SUVmax) of the lymph nodes ranged between 3.4 and 41.9; the nodes were mainly distributed in the neck and axilla regions. Meanwhile, a total of 2502 lymph nodes (721 lymph nodes with a short axis greater than 10 mm) were found in the 38 patients, including 1837 lymph nodes with an 18F-FDG SUVmax ≥ 2.5. The 18F-FDG SUVmax of the spleen ranged from 2.5 to 9.2 in 20 patients, while that of central and peripheral bone marrow ranged from 2.7 to 36.0 in 30 patients. After follow-up for an average period of 1 month, the symptoms improved after prednisone treatment.HNL often occurs in adolescents. Scanning with 18F-FDG PET/CT showed that most patients had multiple involved lymph nodes that were hypermetabolic, and only few lymph nodes are enlarged. Besides, the spleen or central and peripheral bone marrow could sometimes be hypermetabolic. Glucocorticoid treatment for the HNL patients is effective.

[Analysis of the phenotypic heterogeneity of CD123-positive cells in Kikuchi-Fujimoto disease using a sequential immunoperoxidase labeling and erasing method]

Kikuchi-Fujimoto disease (KFD) is a rare disease that is clinically manifested mainly by fever and lymphadenopathy. KFD was originally believed to occur primarily in East Asia women, this disease was subsequently described in all ethnic groups worldwide. The important differential diagnostic feature of KFD is the detection of CD123-expressing plasmocytoid dendritic cells (PDCs) in the tissue of the affected lymph node. The standard immunohistochemical staining method has sufficient sensitivity and specificity to detect CD123, but it gives no way of judging the possible phenotypic heterogeneity of cells with CD123 expression.

OBJECTIVE

To identify the phenotypic heterogeneity of CD123-expressing cells in the affected lymph nodes in patients with KFD by a sequential immunoperoxidase labeling and erasing (SIMPLE) method.

MATERIAL AND METHODS

Excision biopsies of lymph nodes were examined in 3 patients with KFD. After an immunohistochemical reaction using a single antibody, the tissue specimen was digitized with a Pannoramic 250 Flash III scanner (3DHISTECH, Hungary), then the cover glass was removed from the section, the specimen was hydrated and placed in a specialized buffer. Then the following primary antibody was applied to the washed tissue specimen and further immunohistochemical reaction and scanning were performed. As a result, each tissue specimen was sequentially stained in reactions with 4 antibodies. The microphotographs of specimens stained in a reaction with anti-CD123 antibody showed positive cells for their identification in the Pannoramic Viewer program (3DHISTECH, Hungary) on the remaining microphotographs displaying the expression of the other 3 markers. The selected fields of view were exported to a JPG format.

RESULTS

Assessing the co-expression of the antigens CD123, MNDA, CD68, and TCL1A detected 4 CD123+ cell subpopulations: No. 1. CD68+/ MNDA+/ TCL1A+; No. 2. CD68+/ MNDA+/ TCL1A-; No. 3. CD68+/ MNDA-/ TCL1A+; No. 4. CD68-/ MNDA-/ TCL1A+.

CONCLUSION

SIMPLE has shown the phenotypic heterogeneity of CD123-positive cells (some of them may be PDCs) and could identify 4 immunophenotypically distinct subpopulations in the affected lymph nodes in patients with KFD. Further investigations are needed to define the role of subpopulations in the pathogenesis of KFD and other diseases.

Distinguishing lupus lymphadenitis from Kikuchi disease based on clinicopathological features and C4d immunohistochemistry

OBJECTIVES

Distinguishing Kikuchi disease (KD) from lupus lymphadenitis (LL) histologically is nearly impossible. We applied C4d immunohistochemical (IHC) stain to develop diagnostic tools.

METHODS

We retrospectively investigated clinicopathological features and C4d IHC staining in an LL-enriched development cohort (19 LL and 81 KD specimens), proposed risk stratification criteria and trained machine learning models, and validated them in an external cohort (2 LL and 55 KD specimens).

RESULTS

Clinically, we observed that LL was associated with an older average age (33 vs 25 years; P=0.005), higher proportion of biopsy sites other than the neck [4/19 (21%) vs 1/81 (1%); P=0.004], and higher proportion of generalized lymphadenopathy compared with KD [9/16 (56%) vs 7/31 (23%); P=0.028]. Histologically, LL involved a larger tissue area than KD did (P=0.006). LL specimens exhibited more frequent interfollicular pattern [5/19 (26%) vs 3/81 (4%); P=0.001] and plasma cell infiltrates (P=0.002), and less frequent histiocytic infiltrates in the necrotic area (P=0.030). Xanthomatous infiltrates were noted in 6/19 (32%) LL specimens. Immunohistochemically, C4d endothelial staining in the necrotic area [11/17 (65%) vs 2/62 (3%); P<10-7], and capillaries/venules [5/19 (26%) vs 7/81 (9%); P=0.048] and trabecular/hilar vessels [11/18 (61%) vs 8/81 (10%); P<10-4] in the viable area was more common in LL. During validation, both the risk stratification criteria and machine learning models were superior to conventional histological criteria.

CONCLUSIONS

Integrating clinicopathological and C4d findings could distinguish LL from KD.

Case Report: Histiocytic Necrotizing Lymphadenitis (Kikuchi-Fujimoto Disease) Concurrent With Aseptic Meningitis

Kikuchi–Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare, benign, self-limiting disease characterized by local lymphadenopathy. Central nervous system involvement in KFD is extremely rare and remains a diagnostic challenge. Only 41 cases of aseptic meningitis associated with KFD have been reported worldwide, with just four cases (including our case) of KFD with meningitis as the first symptom. We report a case of KFD accompanied by aseptic meningitis with severely high intracranial pressure (400 mmH₂O), increased white blood cell count (56 × 10⁶/L), and moderately elevated protein level (0.52 g/L). This case is unique in the delayed appearance of lymphadenopathy. After 1 month of treatment with steroids, fever, headache, and lymphadenopathy gradually disappeared, and the result of cerebrospinal fluid examination gradually became normal. In conclusion, based on our case findings and our literature review on KFD with aseptic meningitis, a diagnosis of KFD should be considered when delayed appearance of lymphadenopathy is observed in patients with aseptic meningitis.

Kikuchi-Fujimoto Disease Triggered by Systemic Lupus Erythematosus and Mycoplasma pneumoniae Infection-A Report of a Case and a Review of the Literature

ABSTRACT

Kikuchi-Fujimoto disease (KFD) is a necrotizing histiocytic lymphadenitis that was described for the first time in 1972 in Japan. Its etiology is still not fully understood. It has been reported in association with many different agents, diseases, and triggering factors without any conclusive result. To the best of our knowledge, we report for the first time a case of KFD with systemic lupus erythematosus in a child in association with a polymerase chain reaction (PCR)-positive throat swab for Mycoplasma pneumoniae. Although difficult to prove, the acute M. pneumoniae infection might have served as a triggering event for the development of KFD in our case. We encourage further studies to investigate a potential relationship between KFD and M. pneumoniae, which should also use PCR-based testing for this pathogen in patients with KFD.

Clinical and Laboratory Characteristics of Kikuchi-Fujimoto Disease According to Age

Background: Little information exists regarding the differences in the clinical and laboratory characteristics of Kikuchi-Fujimoto disease (KFD) according to age. Objective: To evaluate the clinical and laboratory characteristics of KFD according to age. Methods: The relevance of sex, age, clinical features, laboratory findings, courses, and follow-up results were retrospectively evaluated in patients diagnosed with KFD at Pusan National University Hospital between 2010 and 2020. Results: Eighty patients (46 children and 34 adults) with a mean age of 21.5 ± 11.8 years (range, 3-49 years) were included in the study. Those aged 10-19 years accounted for the largest number of patients (42.5%). Among children, the male sex ratio was higher, especially for patients aged ≤ 9 years. In adults, the female sex ratio was higher, especially for patients aged 20-29 years. Fever, tenderness in the lymph node, and skin rashes were more common in children, while myalgia and weight loss were more common in adults. In children, the recurrence rate was significantly higher among boys than among girls (15.8 vs. 0.0%, P = 0.001); lower platelet count and higher CRP levels were observed among boys than among girls. EBV and ANA positivity rates were higher in boys than in girls. In adults, the recurrence rate was significantly higher in women than in men (18.2 vs. 0.0%, P = 0.005). ANA positivity rates were higher in women than in men. Conclusion: The clinical features, laboratory findings, and recurrence of KFD may differ depending on age and sex. Clinicians should be aware of this.

Kikuchi's disease with hemophagocytic lymphohistiocytosis: A case report and literature review

INTRODUCTION

Kikuchi's disease (KD) is a rare form of necrotizing lymphadenitis that rarely occurs in association with hemophagocytic lymphohistiocytosis (HLH) in children.

PATIENT CONCERNS

We report the case of a 4-year-5-month-old boy who suffered from fever, cervical lymphadenopathy, pancytopenia, hypertriglyceridemia, splenomegaly, low NK cell activity.

DIAGNOSES

A diagnosis of KD with HLH was made based on the results of biopsy of cervical lymph node and HLH-2004 trial guidelines.

INTERVENTIONS

The patient was treated with corticosteroids, cyclosporine, etoposide, continuous hemodiafiltration (HDF), and plasma exchange (PE).

OUTCOMES

He showed a complete response to therapy, and his condition gradually improved. He was discharged on day 45 after admission due to his good recovery status.

CONCLUSION

HLH can be associated with KD, especially in childhood, and may have an aggressive clinical course. Continuous HDF and PE and chemotherapy should be reserved for those patients who fail to respond to IVIG and corticosteroids.

An atypical presentation of Kikuchi-Fujimoto disease: A case report & literature review

The authors urge clinicians to consider the possibility of Kikuchi-Fujimoto Disease associated with autoimmune hemolytic anemia with possible correlation with systemic lupus erythematosus in patients presented with lymphadenopathy and fever.

Rare Presentation of Self-Limiting Kikuchi-Fujimoto Disease in Relapsing Nature

Background

Kikuchi–Fujimoto disease (KFD) is a rare, benign, and self-limiting disease that is commonly associated with cervical lymphadenopathy and fever. The disease has a wide spectrum of clinical manifestations, and definitive diagnosis is based on the histological appearance in the excision biopsy of the lymph nodes. Recurrence of KFD is reported rarely. Case Presentation. A 56-year-old Iranian woman with a background history of thrombocytopenia presented with fever, malaise, loss of appetite, and weight loss with cervical lymphadenopathy. The excision biopsy of the cervical lymph nodes confirmed the diagnosis of KFD, and she made a full recovery with improvement of symptoms, regression of cervical lymph nodes, and normalization inflammatory markers. One year after remission, she presented with similar clinico-biochemical profile, and repeat biopsy confirmed KFD.

Conclusion

Although the rate of recurrence of the disease is very low, the treating physician should consider the possibility and confirm it histologically.

Efficacy of Ultrasound-Guided Needle Biopsy in the Diagnosis of Kikuchi-Fujimoto Disease

OBJECTIVES/HYPOTHESIS

Ultrasound-guided fine-needle aspiration cytology (US-FNAC) is a well-established procedure performed to establish the diagnosis of Kikuchi-Fujimoto disease (KFD). Ultrasound-guided core needle biopsy (US-CNB) is an alternative diagnostic tool for KFD. However, the efficacy of US-CNB is not well evaluated. This study aimed to evaluate the efficacy of US-CNB and compare it with that of US-FNAC in the diagnosis of KFD.

STUDY DESIGN

Retrospective cohort study.

METHODS

We analyzed 170 patients who were diagnosed with KFD between January 2009 and May 2019. US-FNAC, US-CNB, and excisional biopsy were performed in 47, 114, and 9 patients, respectively. Diagnostic accuracies of US-FNAC and US-CNB were analyzed and compared.

RESULTS

Of the 170 patients, 45 and 125 were men and women, respectively. The mean age was 26.9 ± 9.1 years. The most common symptom was cervical lymphadenopathy, followed by fever, headache, and myalgia. The diagnosis of KFD was established primarily by US-FNAC in 21 (44.7%) of the 47 patients, by US-CNB in 109 (95.6%) of the 114 patients, and by excisional biopsy in all 9 patients. There was no specific major complication related to US-FNAC and US-CNB.

CONCLUSION

US-CNB can be considered safe and effective and used as the primary modality for the pathological diagnosis of KFD.

LEVEL OF EVIDENCE

4. Laryngoscope, 131:E1519-E1523, 2021.

Development of Kikuchi-Fujimoto disease after a cervical lymph node metastasis of mucoepidermoid carcinoma: a case report

Kikuchi-Fujimoto disease (KFD) was first reported by Kikuchi and Fujimoto in 1972 as a rare disease with lymphadenitis of unknown etiology. KFD is characterized by the main symptoms of fever and enlarged cervical lymph nodes (LNs), which are similar to the features of other LN-associated diseases. Therefore, it is difficult to diagnose this condition. We report the case of a 24-year-old woman who presented with KFD after surgery to treat a mucoepidermoid carcinoma of the palate and dissection of the left neck. The patient presented with a fever and right cervical lymphadenopathy when she visited our department for a regular follow-up related to the mucoepidermoid carcinoma. The results of computed tomography and ultrasonography evaluations led to a clinical diagnosis of lymph node metastasis, and a right neck dissection was performed. However, the pathological tissue analysis did not suggest malignancy but showed necrosis and various cellular infiltrates. We made a diagnosis of KFD from these clinical and pathological features. KFD may be misdiagnosed as a LN-associated disease such as metastasis. Clinically, KFD should be considered in patients with head and neck cancer who present with cervical lymphadenopathy.

Intensive care management of a rare case of pyrexia of unknown origin (Kikuchi-Fujimoto disease)

Kikuchi-Fujimoto disease is a rare, benign cause of necrotising lymphadenitis often presenting with fever. We describe a case of a 17-year-old boy with non-verbal autism presenting to our intensive care unit with prolonged fever of unknown cause. This case highlights the role of the intensive care unit in cases of diagnostic dilemma. The critical care community should be aware of Kikuchi-Fujimoto disease as although it is usually benign, it can rarely lead to acute airway compromise.

Histology-Independent Signature Distinguishes Kikuchi-Fujimoto Disease/Systemic Lupus Erythematosus-Associated Lymphadenitis From Benign and Malignant Lymphadenopathies

OBJECTIVES

Kikuchi-Fujimoto disease (KFD) and systemic lupus erythematosus (SLE) are benign entities with histologic features that raise concern about malignancy and infection. We searched for a histology-independent KFD/SLE signature relying on only immunophenotype and basic clinical characteristics.

METHODS

A histology-independent KFD/SLE signature was generated using 975 excised lymph nodes with flow immunophenotyping, including 16 cases of KFD/SLE. This signature was then evaluated in 1,198 fine-needle aspiration (FNA) specimens.

RESULTS

The top flow cytometry discriminant for KFD/SLE was uniform CD38+ expression on CD19+ events. Immunohistochemistry demonstrated nodules of IgD+, IgM- B cells surrounding necrotizing and activated T-cell areas. A signature combining 6 flow cytometry criteria with age and sample site had a positive predictive value of 88% for KFD/SLE, which had a prevalence of 1.6%. All 4 signature-positive FNA cases with follow-up excision were KFD/SLE. At a second institution, 4 of 5 KFD/SLE cases passed the top discriminant.

CONCLUSIONS

A flow cytometry signature combined with age and biopsy site identifies KFD/SLE independent of histology, suggesting a shared immune composition and independently confirming that KFD/SLE represents a distinct entity. Unexpectedly, an IgD+CD38+ small B-cell population is a distinctive feature of KFD/SLE, suggesting a possible pathologic role for anergic/autoreactive B cells.

A Case of Kikuchi-Fujimoto Disease Associated with Erosive Lichen Planus

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a benign, self-limiting disorder with unknown etiology. The most frequent clinical manifestations include lymphadenopathy, fever, cutaneous lesions, arthritis, fatigue, and hepatosplenomegaly. Cutaneous manifestations of KFD, occurring in about one-third of patients, are typically non-specific, rarely presenting as symmetrically distributed lesions. The prevalence of erosive lichen planus in patients with KFD, as of this date, is unknown with no previously reported cases describing an association between the two conditions. In the following case report, we report a case presenting with bilateral symmetrical erosive lichen planus of the heel associated with KFD as being a possible, rather novel, cutaneous manifestation.

Cervical lymphadenopathy in children: a diagnostic tree analysis model based on ultrasonographic and clinical findings

OBJECTIVES

To establish a diagnostic tree analysis (DTA) model based on ultrasonography (US) findings and clinical characteristics for differential diagnosis of common causes of cervical lymphadenopathy in children.

METHODS

A total of 242 patients (131 boys, 111 girls; mean age, 11.2 ± 0.3 years; range, 1 month-18 years) with pathologically confirmed Kikuchi disease (n = 127), reactive hyperplasia (n = 64), lymphoma (n = 24), or suppurative lymphadenitis (n = 27) who underwent neck US were included. US images were retrospectively reviewed to assess lymph node (LN) characteristics, and clinical information was collected from patient records. DTA models were created using a classification and regression tree algorithm on the basis of US imaging and clinical findings. The patients were randomly divided into training (70%, 170/242) and validation (30%, 72/242) datasets to assess the diagnostic performance of the DTA models.

RESULTS

In the DTA model based on all predictors, perinodal fat hyperechogenicity, LN echogenicity, and short diameter of the largest LN were significant predictors for differential diagnosis of cervical lymphadenopathy (overall accuracy, 85.3% and 83.3% in the training and validation datasets). In the model based on categorical parameters alone, perinodal fat hyperechogenicity, LN echogenicity, and loss of fatty hilum were significant predictors (overall accuracy, 84.7% and 86.1% in the training and validation datasets).

CONCLUSIONS

Perinodal fat hyperechogenicity, heterogeneous echotexture, short diameter of the largest LN, and loss of fatty hilum were significant US findings in the DTA for differential diagnosis of cervical lymphadenopathy in children.

KEY POINTS

• Diagnostic tree analysis model based on ultrasonography and clinical findings would be helpful in differential diagnosis of pediatric cervical lymphadenopathy. • Significant predictors were perinodal fat hyperechogenicity, heterogeneous echotexture, short diameter of the largest LN, and loss of fatty hilum.

Kikuchi-Fujimoto Disease in Children: An Important Diagnostic Consideration for Cervical Lymphadenitis

Kikuchi-Fujimoto disease (KFD), or histiocytic necrotizing lymphadenitis, is a rare, benign, and self-limited disease that causes lymphadenopathy and has a characteristic histological appearance. The etiology of this disease is unknown, but a possible infectious trigger has been hypothesized. In the adult population this disease is more common in females; however, in the pediatric population it is more common in males. Descriptions in the pediatric literature are lacking, particularly in the United States. The authors report three cases of pediatric KFD that presented at the same institution in a 9-month time period. All three patients were male and of non-Asian descent who were diagnosed with KFD by histopathologic specimen after presenting with unilateral cervical lymphadenitis. Each patient had additional laboratory evidence of a possible bacterial infection at the time of diagnosis. These three cases highlight the importance of considering KFD early when a pediatric patient presents with unilateral cervical lymphadenitis. The authors discuss the epidemiology, etiology, clinical manifestations, diagnostic approaches, and treatment of KFD. [Pediatr Ann. 2019;48(10):e406-e411.].

Distribution of lymphadenopathy in patients with Kikuchi disease

BACKGROUND

Cervical lymphadenopathy is among the cardinal manifestations of Kikuchi disease (KD). The incidences and locations of extra-cervical lymph nodes (LNs) involvement in KD have not been comprehensively reported.

METHODS

From 2003 to 2016, 60 patients with pathologically confirmed KD and with computed tomography and/or whole-body inflammation scans at diagnosis were retrospectively identified. The locations, sizes and characteristics of all affected LNs were analyzed by extensive review of the image studies. The clinical and laboratory parameters were abstracted from medical records and the associations with extra-cervical LNs involvement were identified.

RESULTS

Female accounted for 35 (58.3%) patients and the median age of all patients was 21.3 years (ranges, 3-64 years). Of 59 patients with evaluable neck images, 42 (71.2%) and 16 (27.1%) patients presented with unilateral and bilateral nodal involvement, respectively, with the most common locations at level II, III and IV by Som's classification. The largest LNs appeared most commonly in level II. The incidences of extra-cervical lymphadenopathy in abdomen, pelvis, inguina, axilla and mediastinum with available images were respectively 52.9% (9/17), 47.1% (8/17), 41.2% (7/17), 30.6% (11/36) and 14.3% (8/56). When compared to cases with solitary cervical lymphadenopathy, the cases with extra-cervical lymphadenopathy had significantly greater incidences of bilateral cervical lymphadenopathy (P = .0379) and leukopenia (P = .0173).

CONCLUSION

Unilateral cervical lymphadenopathy was the most frequent form of LNs involvement of KD. Extra-cervical lymphadenopathy was not uncommon and was associated with the appearance of bilateral distribution of cervical LNs and leukopenia.

Kikuchi-Fujimoto Disease: A Review

Kikuchi-Fujimoto disease (KFD) is a rare entity characterized by subacute necrotizing lymphadenopathy and frequently associated with fever. Young adults of Asian ancestry are most commonly affected, but it has been reported worldwide. Despite many studies in the literature, the cause of KFD remains uncertain. Histologically, KFD is characterized by paracortical lymph node expansion with patchy, well-circumscribed areas of necrosis showing abundant karyorrhectic nuclear debris and absence of neutrophils and eosinophils. Three evolving histologic patterns-proliferative, necrotizing, and xanthomatous-have been recognized. By immunohistochemistry, histiocytes in KFD are positive for myeloperoxidase. There is a marked predominance of T cells in the lesions (with mostly CD8-positive cells) with very few B cells. The differential diagnosis of KFD includes infectious lymphadenitis, autoimmune lymphadenopathy (primarily systemic lupus erythematosus), and lymphoma. Clinicians and pathologists are poorly familiar with this entity, which frequently causes significant diagnostic challenges.

Kikuchi-Fujimoto Disease: An Atypical Presentation of a Rare Disease

Kikuchi-Fujimoto disease (KFD), or necrotizing histiocytic lymphadenitis, is a rare cause of lymphadenopathy and fever. Although the clinical course is usually benign, KFD is often mistaken for malignancy or infection. Recognition of typical and atypical cases of KFD is necessary to avoid unnecessary interventions. Here we report an atypical presentation of KFD with diffuse lymphadenopathy and leukocytosis associated with high levels of circulating Epstein-Barr viral DNA.

Take a second look: it's Kikuchi's disease! A case report and review of literature

Generalized lymphadenopathy is a common cause of concern for both patients and clinicians. Possible etiologies include infections, malignancies and autoimmune diseases. Kikuchi Fujimoto disease (KFD) is a hyperergic condition that presents with fever, lymphadenopathy and can include systemic involvement, thus being easily mistaken for the above-mentioned entities. We report the case of a previously healthy 18- year old male who presented with a selflimiting generalized lymphadenopathy, high fevers, skin vasculitis and polyserositis. The lymph-node biopsy revealed a histiocytotic necrotizing lymphadenitis, suggestive of Kikuchi’s disease. This case emphasizes the importance of KFD in the differential diagnosis of lymphadenopathy, especially in young adults.

Persistent cervical lymphadenitis in a patient with prior thyroid cancer attributed to Kikuchi-Fujimoto disease

We describe a 50-year-old woman with a history of thyroid cancer who presented with bilateral cervical and submandibular lymphadenopathy, low-grade fevers, and increasing fatigue. The patient underwent lymph node fine-needle aspiration, which showed no evidence of metastatic or lymphoproliferative disease. This procedure was complicated by a parapharyngeal abscess and cellulitis. She was treated unsuccessfully with various courses of antibiotics, but briefly responded to short courses of steroids. As her cervical lymphadenopathy returned, she underwent an excisional lymph node biopsy, which demonstrated caseating granulomatous lymphadenitis. Extensive review of systems, physical examination, laboratory and imaging studies demonstrated no evidence of malignancy, infection or systemic lupus erythematosus . Our patient was clinically diagnosed with Kikuchi-Fujimoto disease and successfully treated with prednisone tapered over 3 months. She remains in clinical remission.

Kikuchi-Fujimoto disease in children: two case reports and a review of the literature

BACKGROUND

Kikuchi-Fujimoto disease is a rare, idiopathic and generally self-limiting cause of lymphadenitis of unknow etiology with a low recurrence rate. The typical clinical signs are cervical lymphadenopathy, fever, and symptoms of respiratory infection, and less frequently chills, night sweats, arthralgia, rash, and weight loss.

CASE PRESENTATION

Here we describe two case reports of Kikuchi Fujimoto disease presenting in Milan within the space of a few months. The first involved the recurrence of KFD in a young boy from Sri Lanka; the second was a rare case of severe KFD complicated by HLH.

CONCLUSIONS

Pediatricians must consider KFD in the differential diagnosis of fever of unknown origin in children, even in western countries. Although rare, recurrence and severe complications are possible. Where symptoms suggest KFD, a systematic diagnostic approach is key. Since no guidelines on the management of KFD are available, further studies should be conducted to investigate the therapeutic options and long term outcome in children.

Report of a rare case of histiocytic necrotizing lymphadenitis with bilateral pleural effusion diagnosed via cervical lymph node biopsy

CONTEXT

Histiocytic necrotizing lymphadenitis (HNL) is a rare disorder that is often benign and self-limiting. There have been reports of co-occurrence of HNL with other diseases, including systemic lupus erythematosus, hemophagocytic syndrome and antiphospholipid syndrome.

CASE REPORT

Here, we report a case in which a patient experienced unexplained fever, swelling of the cervical lymph node and bilateral pleural effusion and was ultimately diagnosed with HNL based on results from a lymph node biopsy. After treatment with glucocorticoid, the patient regained normal body temperature, the swelling of the lymph nodes disappeared and the pleural effusion was reabsorbed.

CONCLUSIONS

The pathogenesis of HNL remains unclear, and pleural effusion is rarely reported in HNL patients. We presented this case to improve diagnostic awareness of this condition among clinicians and help reduce the likelihood of misdiagnosis.

Acoustic radiation force impulse imaging of biopsy-proven Kikuchi disease: initial experiences for evaluating feasibility in pediatric patients

Purpose

This study evaluated the feasibility of acoustic radiation force impulse (ARFI) elastography and characterized the sonographic features of lymph nodes (LNs) with Kikuchi disease in pediatric patients.

Methods

Seventy-six cervical LN biopsies were performed for the diagnosis of cervical lymphadenopathy. ARFI imaging was performed, and the characteristic ultrasound features of the biopsied LNs and the contralateral LNs were analyzed. We also reviewed clinical and conventional ultrasonographic findings.

Results

On histology, 56 patients were diagnosed with Kikuchi disease. These LNs were large and elongated, with increased perinodal echogenicity and capsular thickening. In 38 of them, ARFI elastography was performed, and the median shear wave velocity (SWV) of the biopsied LNs with Kikuchi disease (2.19 m/sec; range, 1.45 to 4.57 m/sec) was higher than of the contralateral LNs (1.72 m/sec; range, 0.95 to 2.65 m/sec; P<0.001). In patients with reactive hyperplasia, the mean SWV of the biopsied LNs (2.00 m/sec; range, 1.49 to 2.26 m/sec) was higher than that of the contralateral LNs (1.55 m/sec; range, 1.21 to 2.32 m/sec; P=0.031).

Conclusion

The SWV of LNs with Kikuchi disease was significantly higher than that of the contralateral LNs. Morphologically, LNs with Kikuchi disease showed an enlarged, elongated, and oval shape, increased perinodal echogenicity, and capsular thickening. In addition to the conventional ultrasonographic findings, the application of ARFI is feasible even in pediatric patients for the evaluation of cervical lymphadenopathy.

An Unusual Presentation of Kikuchi-Fujimoto Disease with Recurrent Subdural Effusion

A 24-year-old man complained of a right temporal headache for four weeks. The patient denied any trauma or previous anticoagulation use. He also reported tender right facial swelling. His physical exam was unrevealing except for right cranial nerve (CN) VI palsy, right parotid enlargement, and cervical adenopathy. Laboratory findings were significant for mild leukopenia at 3300 cells/uL. The computed tomography (CT) scan obtained showed a chronic left subdural effusion with a 4 mm midline shift and confirmed right parotid enlargement and cervical lymphadenopathy. Surgical burr hole evacuation was done and the fluid was sent for wound culture analysis. The infectious diseases service recommended initiating antibiotics, which were later stopped due to cerebrospinal fluid (CSF) cultures with no growth of any organisms. His CN VI palsy resolved during admission. The patient was discharged with follow-up for biopsy. The patient was lost to follow-up. The patient presented to the emergency department (ED) three months later, with a left-sided frontal headache. A repeat CT scan showed a new, right-sided fluid collection outside the brain parenchyma. Burr hole evacuation was done again and purulent fluid was drained. Antibiotics were held this time, but anti-tuberculous therapy was initiated empirically. The otolaryngology service was consulted and a lymph node biopsy was performed. The pathology showed histiocytic necrotizing lymphadenitis. A dural biopsy was done as well and was consistent with histiocytic necrotizing lymphadenitis involving the dura. Cultures from the subdural fluid did not grow any organism. The patient remained neurologically intact. He improved after surgery was done to drain the fluid and was managed by analgesics. The cultures from the extra-parenchymal fluid collection remained negative for pathogens and tuberculous mycobacteria. The patient was discharged with rheumatology clinic follow-up. He saw the rheumatologist six weeks after the discharge. During his clinic visit, the patient reported no recurrence of headaches, fevers, rash, or joint pain. Our patient had a rare presentation of Kikuchi-Fujimoto disease, in which he had a subdural fluid collection resulting in neurological complications that required surgical intervention.