Kikuchi disease in acute leukaemia: a distinct clinical syndrome with HLA association.

AIMS: To report the clinicopathological features of Kikuchi disease in patients with acute leukaemia, emphasising similarities among cases. METHODS AND RESULTS: In a cohort of 454 Kikuchi disease patients, we identified three cases of concurrent acute leukaemia. These patients shared similar clinical traits, with Kikuchi disease emerging approximately a month after induction chemotherapy onset, featuring neck-region lymphadenopathy. Notably, two patients were middle-aged, deviating from the typical age distribution of Kikuchi disease. Histologically, these cases aligned with typical Kikuchi disease. Negative immunohistochemical stains (CD34, CD117, ERG, TdT) indicated the absence of extramedullary leukaemic infiltration. Herpes simplex virus immunohistochemical staining was also negative. Significantly, a human leucocyte antigen (HLA) association was observed in these three cases. HLA-B*15:01, C*04:01, and DRB1*04:06 were more prevalent in these patients compared to the general population (compared with three independent control cohorts: Taiwanese Han Chinese (n = 504), Tzu Chi Taiwanese bone marrow donors (n = 364) and Hong Kong Chinese (n = 5266)). CONCLUSIONS: Our study underscores the unique link between Kikuchi disease and acute leukaemia, characterised by specific features and HLA associations. This underlines Kikuchi disease as a possible differential diagnosis in pertinent clinical scenarios. Furthermore, this syndrome offers insights into postchemotherapy immunology in acute leukaemia, enhancing comprehension.

Hemophagocytic lymphohistiocytosis and histiocytic necrotizing lymphadenitis secondary to hemodialysis catheter-related bloodstream infection caused by Corynebacterium Striatum.

BACKGROUND: We herein described the coexistence of hemophagocytic lymphohistiocytosis (HLH) and histiocytic necrotizing lymphadenitis, alternatively known as the Kikuchi disease (KD), secondary to hemodialysis catheter-related bloodstream infection (BSI) caused by Corynebacterium striatum. CASE PRESENTATION: A patient on maintenance hemodialysis had developed persistent fever and Corynebacterium striatum was subsequently identified from the culture of both catheter tip and peripheral blood. During mitigation of the BSI, however, his fever was unabated and ensuing workup further found thrombocytopenia, hyperferritinemia, hypertriglyceridemia, low NK cell activity and a surge in serum CD25 levels. Moreover, biopsy of the bone marrow and lymph node detected histopathological evidence of hemophagocytosis and KD, respectively. Upon these abnormalities, the title-bound diagnosis was considered and the patient was eventually recovered from the treatment of dexamethasone instead of antibiotics. Consistently, aberrations in his serum CD25 levels and NK cell activity had subsided two months after discharge. CONCLUSIONS: Arguably, this encounter offered a unique chance to unravel the principal pathogenic cascade in immunobiology that made the three entities one disease continuum. As such, our work may add new understandings of HLH and/or KD secondary to severe infections in general and excessive release of cytokines in particular among patients with kidney diseases. The resultant early diagnosis is crucial to initiate appropriate treatment and improve the survival of patients with these challenging and potentially life-threatening disorders.

Cutaneous Kikuchi disease-like inflammatory pattern without lymph node involvement is associated with systemic disease and severe features in lupus erythematous: A case-control study.

INTRODUCTION: Kikuchi-Fujimoto disease (KFD) is a self-limited histiocytic necrotizing lymphadenitis sometimes affecting the skin. "Kikuchi disease-like inflammatory pattern" (KLIP) has been described in cutaneous lesions as similar pathological features in patients without lymph node involvement and as a potential clue for the diagnosis of lupus. We aimed to describe KLIP-associated clinical and immunological features in lupus patients with a retrospective case-control study. METHODS: Thirteen cases of KLIP were included as well as thirty-nine age- and sex-matched control lupus patients without KLIP. At the time of KLIP diagnosis, 4/13 patients (31%) had isolated cutaneous lupus erythematosus (CLE) and 9/13 had (69%) systemic lupus erythematosus (SLE) including 6 (46%) with severe haematological, lung, cardiac or renal disease. KLIP features were observed in skin biopsies of different clinical presentations. RESULTS: Compared with our control group, KLIP patients more frequently had SLE 9/13 (69%) versus 8/39 (21%) (OR 12.9; IC95% [2.86-58.2]; p = 0.0004) and more frequently severe SLE. Two out of four CLE exhibiting KLIP lesions (50%) developed severe SLE with cardiac or renal involvement after 12 and 24 months, respectively.Treatment with thalidomide 100 mg/day allowed rapid and complete clearance of cutaneous lesions in 6/6 KLIP patients. The need to use thalidomide tended to be more frequent in KLIP patients than in controls. CONCLUSION: Our study suggests that KLIP features in lupus skin lesions are associated with SLE and severe systemic features. Despite a limited number of isolated CLE patients with KLIP features in the skin, this observation may warrant closer follow-up on patients with a higher risk of developing SLE.

Kikuchi Cervical Lymphadenitis in Children: Ultrasound Differentiation From Common Infectious Lymphadenitis.

OBJECTIVES: To investigate ultrasound (US) features of enlarged cervical lymph nodes (LNs) to differentiate between Kikuchi disease (KD) and other common types of infectious lymphadenitis in an East Asian pediatric patient population. METHODS: A total of 142 pediatric patients with KD and 45 patients with infectious lymphadenitis (suppurative lymphadenitis [n = 29], nontuberculous mycobacterial lymphadenitis [n = 9], and tuberculous lymphadenitis [n = 7]) were included. The clinical characteristics, laboratory results, and US features of LNs were reviewed. The area under the curve (AUC) from a receiver operating characteristic curve analysis was used as a diagnostic accuracy measure. RESULTS: A multiple clustered adjacent pattern, bilaterality, an even size, posterior neck involvement, no enlargement, an elongated-to-ovoid shape, homogeneous hypoechogenicity, a well-defined margin, presence of an echogenic fatty hilum, no intranodal gross necrosis, increased perinodal fat echogenicity, and no increased echogenicity of the adjacent sternocleidomastoid muscle were significant US features of the affected LNs to discriminate KD from infectious lymphadenitis (P < .05). Homogeneous hypoechogenicity in KD showed the highest AUC (0.930) as a single variable (95% confidence interval, 0.88-0.96). The AUCs were increased in 3 combination models with 2 US features: homogeneous echogenicity and 1 of 3 other US features (increased perinodal fat echogenicity, 0.935; number of affected LNs, 0.947; and LN shape, 0.949). CONCLUSIONS: Homogeneous hypoechogenicity of LNs was a significant US feature with the highest diagnostic accuracy in differentiating KD from common infectious lymphadenitis on a univariate analysis. In the combination model, US features of an elongated-to-ovoid shape and homogeneous hypoechogenicity showed the highest diagnostic accuracy.

Kikuchi disease as a possible cause of ischaemic stroke: a case report.

INTRODUCTION: Kikuchi disease (KFD) is a rare and self-limiting benign disease which usually occurs in young women. The difference between our case and the previous case is that the initial symptom of this case is transient ischemic attack (TIA). METHODS: A 46-year-old female patient presented at the clinic with a 2-week history of paroxysmal left limb weakness and fever. Imaging examinations showed the multiple lymph nodes in neck enlarged bilaterally. Finally, we arranged a lymph node biopsy for the patient. RESULTS: The resulted of lymph node biopsy showed the disorder of lymph node structures, widespread histiocytic infiltration and cell nucleus fragments, suggesting KFD. CONCLUSION: TIA as a complication of KFD has never been reported in the previous literature, which provided a new direction for diagnosis of TIA and suggested that KFD may be a rare cause of ischemic stroke.

HIV and systemic lupus erythematosus: where immunodeficiency meets autoimmunity.

We report a case of a new diagnosis of systemic lupus erythematosus (SLE) in a patient with HIV who presented to the outpatient department with a fever, headache and lymphadenopathy. Cerebrospinal fluid analysis showed lymphocytic pleocytosis. Initial concerns were for an infectious process, and investigations for systemic and central nervous system infection were negative. Serum testing for ANA, dsDNA, nucleosome, anti-histone and ribosomal-P antibodies was positive. A magnetic brain imaging scan of the brain showed a well-circumscribed lesion in the right cerebellar peduncle on T2/FLAIR. The patient was commenced on prednisolone and rituximab, and had a good clinical response. The cerebellar lesion resolved and has not recurred with sequential imaging. SLE and HIV are both multi-systemic diseases which rarely co-occur. Autoimmune processes should be considered in HIV patients with multi-systemic symptoms and signs.

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.

AIM: Kikuchi-Fujimoto disease (KFD) is an important cause of lymphadenitis in children. The primary aim of this study was to investigate the clinical characteristics of children with KFD and to assess the recurrence of this disease. METHODS: This is a retrospective study of patients younger than 18 years old, who were diagnosed with KFD from January 2000 to September 2017 at KK Women's and Children's Hospital. Records of children with a histological diagnosis of KFD from a lymph node biopsy were obtained from the Department of Pathology. Case notes and electronic medical records of the patients were reviewed. Data collected included patient characteristics, symptoms, clinical and laboratory findings, treatment and follow-up. RESULTS: A total of 98 patients were identified. There were 52 boys and 46 girls with a median age of 11.2 years old. Recurrence occurred in 12 (12.2%) patients. One patient developed systemic lupus erythematosus 10 years after diagnosis of KFD. Recurrent cases were more likely to be managed as an inpatient and have fever at presentation of their first episode of KFD. CONCLUSION: In our study, KFD in children had a higher prevalence among boys, and had a recurrence rate of 12.2%, with 1% of patients developing systemic lupus erythematosus. We recommend that patients be followed up for recurrence and advised to monitor for symptoms of recurrence.

Diagnosing Kikuchi's disease on fine needle aspiration biopsy.

OBJECTIVE: To investigate the diagnostic utility of fine needle aspiration (FNA) smear, cell block (CB), flow cytometry (FC) and tuberculosis polymerase chain reaction (Tb-PCR) analysis for Kikuchi's disease (KD). METHODS: A total of 173 FNA biopsy samples were collected using a Youyi aspirator. KD was diagnosed by FNA smear, with or without, CB, FC and Tb-PCR. RESULTS: Out of 173 patients, 131 (75.7%) were female and 126 (72.8%) aged 21-40 years. Of these, 171 patients (98.8%) presented with painful enlarged cervical lymph nodes. All cytological samples identified intracellular apoptotic debris embedded in the cytoplasm of crescentic and phagocytic macrophages. In 24 cell-blocks (CBs), clusters of CD123 positive plasmacytoid monocytes were observed in KD. FC and CBs showed non-specific lymphoid hyperplasia in nine cases with suspicious lymphoma. Tb-PCR was negative in five cases with suspicion of tuberculosis. CONCLUSIONS: In summary, FNA biopsy is a fast, reliable, and relatively inexpensive diagnosis tool for KD. CB preparation is an important adjunct method for the diagnosis of KD.

Kikuchi Disease: A Case Report.

BACKGROUND: Kikuchi disease, also known as Kikuchi-Fujimoto disease, is a rare, benign cause of cervical lymphadenitis. It is characterized by painful cervical lymphadenopathy with fevers, leukopenia, and an elevated erythrocyte sedimentation rate. It is diagnosed by obtaining a biopsy specimen from a lymph node that shows characteristic histopathologic findings. CASE REPORT: We highlight a 42-year-old Japanese man who presented with persistent fevers and cervical lymphadenopathy who was misdiagnosed at multiple urgent care facilities and emergency departments. He was eventually diagnosed with Kikuchi disease after a biopsy specimen was obtained from a lymph node 1 month after his symptoms began. He was treated with hydroxychloroquine and prednisone with resolution of his symptoms. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although Kikuchi disease has been previously described in various specialty medical journals, the published literature on Kikuchi disease in emergency medicine is relatively scarce. Given that cervical lymphadenopathy is a common presentation to emergency departments, it is important for emergency physicians to be cognizant of Kikuchi disease in the differential diagnosis of cervical lymphadenopathy to prevent misdiagnoses and unnecessary treatments.

A rare presentation of Kikuchi Disease with Hemolytic Uremic Syndrome.

Kikuchi disease (KD) or also known as Kikuchi Fujimoto disease is named after scientists Kikuchi and Fujimoto who describe the disease in Japan in 1972. KD originally reported from Asia but later case reports from different regions of world have been published. It is a benign condition of necrotizing histiocytic lymphadenitis which mimic like Lymphoma, diagnosis of KD is based on histo-pathological findings from lymphnodes. It is a rare condition and mostly case reports have been published, it can have an association with other pathologies. We aim to report a case where KD has been found in a young woman in association with hemolytic uremic syndrome and acute kidney injury.

Real-time elastography of cervical lymph nodes in Kikuchi disease.

We report, to our knowledge, the first cases of sonographic and real-time elastographic findings of cervical lymph nodes in patients with Kikuchi disease. Cervical lymph nodes had probably benign findings on grayscale sonography and real-time elastography.

Kikuchi-Fujimoto disease, a rare benign disease with atypical histomorphology: more than meets the eye.

Kikuchi-Fujimoto disease (KFD) is a benign self-limiting condition primarily affecting young females. It usually presents with fever and cervical lymphadenopathy of unknown aetiology with a preponderance of the Asian population. Histopathology is critical in making an accurate diagnosis. While the typical microscopic features include paracortical necrosis with debris, histiocytosis with immunoblasts, and absent neutrophils, rarely, KFD can show atypical features like marked immunoblastic proliferation mimicking lymphoma, demonstrate vasculitis mimicking lupus erythematosus, etc. The diagnosis is extremely challenging if such features occur in cases with generalised lymphadenopathy, which is infrequent in KFD. The study aims to describe the morphological, clinical, and immunohistochemical features of KFD and determine the frequency of the atypical features. We also analysed the subtle histological and immunohistochemical features that aid in the diagnosis of atypical cases. Cases reported as KFD over a period of 6 years were retrieved from the archives of histopathology. The morphological features were categorised as typical and atypical. In the atypical cases, the features that aided in the correct diagnosis of KFD were analysed. Out of the 42 cases evaluated, 23.9% (n=10) had generalised lymphadenopathy; 57.2% (n=24) were women with a median age of 25 years. Leukopenia was observed in 42% (n=13) of patients. Typical features were present in 76.2% (n=32) cases and 23.8% (n=10) presented with atypical features. Eight cases were antinuclear antibody-positive. Atypical features included five (50%) cases with vasculitis and panniculitis, and three (30%) cases with large, atypical cells for which immunohistochemistry (IHC) was performed. In two of these cases, the patent sinuses, absence of neutrophils, and IHC with CD68 aided the diagnosis. There is an overlap of clinical and histopathological features between KFD and malignant lymphomas and systemic lupus erythematosus. Given the fact that the atypical features (23.8%) are not rare occurrences in KFD, correlations with clinical findings and ancillary studies are essential to avoid misdiagnosis and inadvertent therapy.

Multiple Painless Cervical Lymphadenopathies Misleading the Diagnosis of Kikuchi's Disease.

Kikuchi's disease is an unusual and self-limited disease. It manifests as a painful cervical lymphadenopathy and is associated with a low-grade fever and night sweats. Recently, this disease has been reported worldwide, compared to its initial high prevalence among the Japanese population. The etiologies of Kikuchi's disease are still unknown, but it has been proposed to have either infectious or immunological causes. We report the atypical presentation of a young male with Kikuchi's disease. A 22-year-old male presented with a prolonged fever for a week, which was associated with bilateral neck swelling that was painless and gradually increased in size. In our case, histopathological examination of the left cervical lymph node revealed histiocytic necrotizing lymphadenitis in favor of Kikuchi's disease. This case report will highlight the atypical clinical presentation of this patient, thereby increasing awareness of the disease's future manifestation.

Kikuchi disease: A case report about Sintilimab-induced Kikuchi histiocytic necrotizing lymphadenitis and literature review.

Immune checkpoint inhibitors have become one of the effective means of solid tumor treatment, among which anti-programmed death-1 (PD-1) antibodies are more maturely applied and can effectively inhibit tumor immune escape, thus enhancing the anti-tumor effect, but it can also lead to a series of immune-related adverse events (irAEs) in the process of clinical use. Here, we report a Patient with pancreatic solid pseudopapilloma treated with Sintilimab for the fifteenth cycles who developed chills, fever, and lymph node enlargement. Considering that the patient did not have infection, without history of autoimmune disease, we diagnosed the patient with Sintilimab-induced histiocytic necrotizing lymphadenitis (Kikuchi disease). The symptoms are alleviated after rapid use of glucocorticoids. Histiocytic necrotizing lymphadenitis (Kikuchi lymphadenitis) with anti-programmed death-1 (PD-1) antibody is a rare immune-related adverse events (irAEs).

Kikuchi-Fujimoto disease following SARS-CoV-2 infection: A rare disease with increased incidence during the COVID-19 pandemic?

Kikuchi-Fujimoto Disease (KFD), also known as Kikuchi disease or Kikuchi histiocytic necrotizing lymphadenitis, is a rare and self-limiting condition characterized by cervical lymphadenopathy and fever, primarily affecting young Asian adults. The aetiology of KFD remains unknown, although various infectious agents have been suggested as potential triggers. With the emergence of the COVID-19 pandemic, cases of post-COVID-19 KFD and post-COVID-19 vaccine KFD have been reported. In this article, we present the first case of post-COVID-19 KFD in Hong Kong. A 24-year-old man developed fever and painful neck swelling 1 month after recovering from COVID-19. Diagnostic evaluation, including ultrasound-guided fine needle aspiration cytology (FNAC), confirmed the diagnosis of KFD. The patient's symptoms resolved spontaneously with supportive care. This case underscores the importance of considering KFD as a potential differential diagnosis in patients presenting with cervical lymphadenopathy and fever following COVID-19 recovery or vaccination.

Serum Soluble IL-2 Receptors Are Elevated in Febrile Illnesses and Useful for Differentiating Clinically Similar Malignant Lymphomas from Kikuchi Disease: A Cross-Sectional Study.

Background: The use of serum soluble interleukin 2 receptor (sIL-2R) for the diagnosis of febrile illnesses has not been examined. In this study, febrile patients were classified according to etiology and disease, and serum sIL-2R levels were evaluated. We determined whether serum sIL-2R is a useful marker for differentiating between malignant lymphoma (ML) and non-ML patients and between patients with ML and Kikuchi disease, which present similar clinical manifestations. Methods: This study was a cross-sectional study and included 344 patients with uncomplicated hemophagocytic syndrome, who had a fever of 38 °C or higher within 1 week of admission to our institution. Patient serum sIL-2R was measured, and the serum sIL-2R values are shown as median and IQR. Results: Serum sIL-2R increased above the upper reference limit in all disease groups with fever. The serum sIL-2R level in ML patients (n = 13) was 4760 (2120-6730) U/mL and significantly higher (p < 0.001) than the level of 998 (640-1625) U/mL in non-ML patients (n = 331). The serum sIL-2R level in ML patients (n = 13) was also significantly higher (p < 0.001) compared with that in patients with Kikuchi disease (n = 20; 705 (538-1091) U/mL). Conclusions: Serum sIL-2R tends to exceed the upper reference limit in patients with febrile illnesses. We conclude that the measurement of serum sIL-2R is useful for differentiating ML from non-ML and ML from Kikuchi disease.

When the Lightning Strikes Twice: Navigating the Complex Terrain of Cerebral Tuberculosis.

Tuberculosis (TB), a Mycobacterium tuberculosis (Mtb) infection, remains a significant global health concern despite a declining incidence. This report highlights a complex case involving a 24-year-old patient from Angola who presented with a constellation of symptoms, including fever, weight loss, and neurological deficits. The patient had been on chronic corticosteroid therapy, a known risk factor for the reactivation of latent TB infection (LTBI). Her clinical course was marked by diagnostic challenges, such as a previous diagnosis of Kikuchi's disease and paradoxical progression despite appropriate tuberculostatic chemotherapy. Miliary TB, characterized by widespread dissemination of Mtb from the primary site of infection, can manifest in various extrapulmonary locations. Central nervous system (CNS) involvement, particularly TB meningitis, is the most severe form of TB, associated with significant morbidity and mortality. The diagnosis of miliary and CNS TB can be elusive due to nonspecific clinical presentations and imaging findings. This case underscores the importance of a high index of suspicion, especially in immunocompromised individuals, and the need for comprehensive microbiological analysis, including cerebrospinal fluid (CSF) examination, to confirm CNS involvement. Furthermore, this case illustrates the challenges associated with TB treatment, including the risk of drug toxicity, medication adherence, and the potential for drug resistance. Treatment duration for miliary TB is extended, typically lasting nine months to a year, and may require adaptation based on the patient's clinical response and drug penetration into the CNS. Corticosteroids play a critical role as adjuvant therapy, particularly in cases with perilesional edema or paradoxical reactions during treatment. This case underscores the complexity of diagnosing and managing miliary and CNS TB, emphasizing the importance of considering TB as a diagnostic possibility in patients with nonspecific symptoms and risk factors. Early identification, multidisciplinary collaboration, and tailored therapeutic strategies are essential for achieving optimal outcomes in such challenging cases. Additionally, screening for latent TB infection should be a priority for patients requiring immunosuppressive therapy to mitigate the risk of reactivation.

A young Saudi female with combined hemophagocytic lympho-histiocytosis and Kikuchi's disease: A case report.

Kikuchi's disease is an idiopathic self-limiting condition first reported in Japan in 1972. However, hemophagocytic lympho-histiocytosis is a condition that occurs due to overstimulation of the immune system. The presence of the two conditions is rare, and the clinical observation of this unusual clinical syndrome is worth reporting. We are reporting an 18-year-old Saudi female patient who presented with high-grade fever and diaphoresis 3 weeks before her presentation. Physical examination showed palpable cervical and axillary lymphadenopathy; laboratory investigation found neutropenia, a high lactate dehydrogenase of 550 U/L, and high ferritin levels. A thoracoabdominal computed tomographic study revealed generalized lymphadenopathy. She was diagnosed with hemophagocytic lympho-histiocytosis based on a bone marrow biopsy finding and Kikuchi's disease based on an excisional cervical lymph node biopsy. She received a high dose of dexamethasone with complete resolution of the condition. In conclusion, hemophagocytic lympho-histiocytosis and Kikuchi's Disease are uncommon conditions. The presence of a combination of such two conditions is extremely rare and worth reporting. Early diagnosis and initiation of the management with high dexamethasone dose could save patient life.