Kikuchi-Fujimoto lymphadenitis

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.

Kikuchi-Fujimoto disease during early pregnancy

Kikuchi-Fujimoto disease (KFD) is rare during pregnancy. It is characterized by necrotizing lymphadenitis and often occurs in young Asian women. We report a case of KFD during pregnancy, which was difficult to diagnose. A 37-year-old pregnant female (gestational week [GW] 7+5) was admitted to our hospital because of hyperemesis gravidarum. On the eighth day of hospitalization (GW 8+6), she suddenly developed a fever (38.0°C) with skin rash and posterior pharynx redness. Blood tests showed pancytopenia and abnormal liver function. The patient was misdiagnosed with severe Epstein-Barr virus infection and administered with prednisolone. Subsequently, cervical lymphadenopathy was observed, and biopsy results led to the diagnosis of KFD. Thereafter, her symptoms improved, and she was discharged at GW 13+4. KFD must be included as a differential diagnosis for patients with fever, abnormal liver function, and pancytopenia during pregnancy.

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.

Necrotizing lymphadenitis : A case report and literature review

BACKGROUND

Necrotizing lymphadenitis is a rare disease. It is often misdiagnosed because of the lack of typical clinical manifestations. It is worth noting that necrotizing lymphadenitis may be a precursor lesion of systemic lupus erythematosus or tumours, so regular follow-up is needed to facilitate early diagnosis. Here, we report a case and conduct a literature analysis summarizing the clinical features of necrotizing lymphadenitis and its treatment and management practices.

CASE PRESENTATION

A 16-year-old young woman presented with fever and lymphadenopathy as the main clinical manifestations, accompanied by a rash during fever that disappeared as the fever subsided. After completing imaging and laboratory examinations, we excluded other diseases such as infections, autoimmune diseases, and malignant tumours. Finally, we diagnosed the patient with necrotizing lymphadenitis based on the results of lymph node biopsy. The symptoms of the patient improved after glucocorticoid treatment, and she was followed up for half a year without recurrence of symptoms.

CONCLUSION

In the clinic, young women with fever and lymphadenopathy as major symptoms should be screened for necrotizing lymphadenitis to facilitate early diagnosis and treatment. Although necrotizing lymphadenitis is self-limiting, its clinical manifestations are similar to those of many diseases. Therefore, it is easily misdiagnosed. An in-depth understanding of the disease is conducive to early diagnosis and treatment in the clinic, thereby reducing further damage to the body and reducing unnecessary evaluation and treatment.

Immunopathology of Kikuchi-Fujimoto disease: A reappraisal using novel immunohistochemistry markers

AIMS

Kikuchi-Fujimoto disease (KFD) is a self-limited disease characterised by destruction of the lymph node parenchyma. Few studies have assessed the immunohistological features of KFD, and most employed limited antibody panels that lacked many of the novel immunohistochemistry markers currently available.

METHODS AND RESULTS

We used immunohistochemistry to reappraise the microanatomical distribution of plasmacytoid dendritic cells (pDCs), follicular helper T cells and cytotoxic T cells, B cells, follicular dendritic cell (FDC) meshworks, and histiocytes in lymph nodes involved by KFD. The study group consisted of 138 KFD patients (89 women; 64.5%) with a median age of 27 years (range, 3-50 years). Cervical lymph nodes were most commonly involved, in 108 (78.3%) patients. The numbers of pDCs were increased, predominantly around and within apoptotic areas and the paracortex, and tapering off within xanthomatous areas. pDCs formed sizeable tight clusters, most notably around apoptotic/necrotic areas. T cells consisted mostly of CD8-positive cells with predominant expression of T-cell receptor-β. There were notable increases in the numbers of CD8-positive T cells within lymphoid follicles, and their numbers correlated with alterations in FDC meshworks (P < 0.001). The number of follicular helper T cells was decreased within distorted FDC meshworks. CD21 highlighted frequent distortion of FDC meshworks, even in lymph node tissue that was distant from apoptotic/necrotic areas. Distorted FDC meshworks spanned all morphological patterns, and FDC meshwork characteristics (intact; distorted; remnant/nearly absent) correlated with morphological patterns (P < 0.01).

CONCLUSIONS

The immunohistological landscape of KFD is complex and characterised by increased numbers of pDCs that frequently cluster around apoptotic/necrotic foci, increased numbers of cytotoxic T cells, and substantial distortion of FDC meshworks.

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.

Approach to nodal-based T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) represent a heterogeneous group of uncommon malignancies derived from mature T cells and usually characterised by an aggressive clinical course. Their clinical presentation, localisation and pattern of dissemination are highly variable, but the majority of cases present as nodal diseases. The recently revised classification of lymphomas has incorporated many new molecular genetic data derived from gene expression profiling and next generation sequencing studies, which refine the definition and diagnostic criteria of several entities. Nevertheless, the distinction of PTCL from various reactive conditions, and the diagnosis of PTCL subtypes remains notably challenging. Here, an updated summary of the clinicopathological and molecular features of the most common nodal-based PTCLs (angioimmunoblastic T-cell lymphoma and other nodal lymphomas derived from follicular T helper cells, anaplastic large cell lymphomas and peripheral T-cell lymphoma, not otherwise specified) is presented. Practical recommendations in the diagnostic approach to nodal T-cell lymphoproliferations are presented, including indications for the appropriate use and interpretation of ancillary studies. Finally, we discuss commonly encountered diagnostic problems, including pitfalls and mimics in the differential diagnosis with various reactive conditions, and the criteria that allow proper identification of distinct PTCL entities.

Cervical necrotic lymphadenopathy: a diagnostic tree analysis model based on CT and clinical findings

OBJECTIVES

To establish a diagnostic tree analysis (DTA) model based on computed tomography (CT) findings and clinical information for differential diagnosis of cervical necrotic lymphadenopathy, especially in regions where tuberculous lymphadenitis and Kikuchi disease are common.

METHODS

A total of 290 patients (147 men and 143 women; mean age (years), 46.2 ± 19.5; range, 3-91) with pathologically confirmed metastasis (n = 110), tuberculous lymphadenitis (n = 73), Kikuchi disease (n = 71), and lymphoma (n = 36) who underwent contrast-enhanced neck CT were included. The patients were randomly divided into training (86%, 248/290) and validation (14%, 42/290) datasets to assess diagnostic performance of the DTA model. Two sorts of DTA models were created using a classification and regression tree algorithm on the basis of CT findings alone and that combined with clinical findings.

RESULTS

In the DTA model based on CT findings alone, perinodal infiltration, number of the necrotic foci, percentage of necrotic lymph node (LN), degree of necrosis, margin and shape of the necrotic portion, shape of the LN, and enhancement ratio (cutoff value, 1.93) were significant predictors for differential diagnosis of cervical necrotic lymphadenopathy. The overall accuracy was 80.6% and 73.8% in training and validation datasets. In the model based on imaging and clinical findings, tenderness, history of underlying malignancy, percentage of necrotic LN, degree of necrosis, and number of necrotic foci were significant predictors. The overall accuracy was 87.1% and 88.1% in training and external validation datasets.

CONCLUSIONS

The DTA model based on CT imaging and clinical findings may be helpful for the diagnosis of cervical necrotic lymphadenopathy.

KEY POINTS

• The diagnostic tree analysis model based on CT may be useful for differential diagnosis of cervical necrotic lymphadenopathy. • Perinodal infiltration, number of necrotic foci, percentage of necrotic lymph nodes, degree of necrosis, margin and shape of necrotic portion, lymph node shape, and enhancement ratio were the most significant predictors.

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.

Comparison of Ultrasonographic Findings of Biopsy-Proven Tuberculous Lymphadenitis and Kikuchi Disease

Objective

Although tuberculous lymphadenitis and Kikuchi disease are common causes of cervical lymphadenopathy in Asians and exhibit similar clinical manifestations, their treatment strategies are totally different. The purpose of this study was to identify ultrasonographic features that distinguish these two diseases.

Materials and Methods

This study was approved by the Institutional Review Board. The study included 77 patients with tuberculous lymphadenitis and 135 patients with Kikuchi disease. The sex and age distributions of the patients were analyzed. The size and shape of lymph nodes (LNs), presence of conglomeration, increased perinodal echogenicity, echogenic hilum, posterior neck involvement, internal calcification, patterns of internal necrosis, laterality of involved LNs, and hilar vascular patterns on ultrasonography were compared between the two groups. Multiple logistic regression analysis was conducted to identify independent findings to discriminate tuberculous lymphadenitis from Kikuchi disease. Finally, diagnostic accuracies were calculated using the independent findings.

Results

The presence of an echogenic hilum, internal calcification, patterns of internal necrosis, and LN hilar vascular structures on power Doppler ultrasonography were independent findings that discriminated tuberculous lymphadenitis from Kikuchi disease. The diagnostic accuracy of each of these four factors was 84.9% (181/212), 76.9% (163/212), 84% (178/212), and 89.2% (189/212), respectively. A combination of internal calcification and hilar vascular structures showed the best accuracy of 89.6% (190/212) (sensitivity, 86.7% [117/135]; specificity, 94.8% [73/77]) for diagnosing Kikuchi disease.

Conclusion

The presence of an echogenic hilum, internal calcification, pattern of internal necrosis, and LN hilar vascular structures are useful ultrasonographic findings to differentiate tuberculous lymphadenitis from Kikuchi disease.

Kikuchi-Fujimoto Disease Masquerading as Metastatic Papillary Carcinoma of the Thyroid

Kikuchi-Fujimoto disease also known as histiocytic necrotizing lymphadenitis is a rare cervical inflammatory lymphadenitis that is most commonly seen in young Asian women. It is mainly characterized by lymphadenopathy, hepatosplenomegaly, fever, nocturnal sweats, myalgia, weight loss, and arthralgia, and commonly follows a self-limited course. The differential diagnosis is challenging as many other conditions such as malignant lymphoma, metastatic disease, tuberculosis and infectious lymphadenopathies can present in a similar way. We present an unusual case of Kikuchi-Fujimoto disease masquerading as metastatic papillary carcinoma of the thyroid. A 30-year-old young female presented, 2 months post-partum, with complaints of neck pain and fever. A computed tomography scan showed enlarged right-sided lymph nodes and a thyroid nodule. Subsequent biopsy of a thyroid nodule revealed papillary thyroid carcinoma and reactive inflammation in one of the lymph nodes. She underwent an elective total thyroidectomy, central node dissection and a right modified lymph node dissection for enlarged lymph nodes. Her recovery was uneventful and the pathology report was consistent with a papillary carcinoma of the thyroid with one lymph node positive for metastatic disease and several other lymph nodes showing histiocytic necrotizing lymphadenitis. This coexistence of Kikuchi-Fujimoto disease with localized metastatic papillary thyroid cancer is unusual and presents an interesting, challenging, and complex management dilemma.

Pathogenesis, diagnosis, and management of Kikuchi-Fujimoto disease

BACKGROUND

Kikuchi-Fujimoto disease (KFD) is a rare lymphohistiocytic disorder with an unknown etiopathogenesis. This disease is misdiagnosed as malignant lymphoma in up to one-third of cases and is associated with the development of systemic lupus erythematosus (SLE).

METHODS

The medical literature between the years 1972 and 2014 was searched for KFD, and the data were collected and analyzed regarding the epidemiology, clinical presentations, diagnosis, management, and suggested diagnostic and treatment algorithms.

RESULTS

Although KFD has been reported in other ethnic groups and geographical areas, it is more frequently diagnosed in young women of Asian descent. Patients with the disease typically present with rapidly evolving tender cervical lymphadenopathy, night sweats, fevers, and headache. Diagnosis is based on histopathological examination. Excisional lymph node biopsy is essential for a correct diagnosis. Apoptotic coagulation necrosis with karyorrhectic debris and the proliferation of histiocytes, plasmacytoid dendritic cells, and CD8(+) T cells in the absence of neutrophils are characteristic cytomorphology features. Interface dermatitis at the onset of KFD may be a marker for the subsequent evolution of SLE. The natural course of the disease is typically benign. Short courses of steroids, nonsteroidal anti-inflammatory drugs, or hydroxychloroquine can be administered to patients with more severe symptoms.

CONCLUSIONS

Although KFD was described more than 40 years ago, the etiology of this disease remains unsolved. Infectious or autoimmune processes were proposed but have not been definitively confirmed. Clinical presentation with systemic B symptoms and adenopathy may lead to an erroneous diagnosis of malignant lymphoma. The introduction of modern methods into hematopathology, including immunohistochemistry, flow cytometry, and molecular clonality studies, has decreased the probability of misdiagnosis. Until reliable prognostic markers are available, patients with KFD should have continued long-term follow-up care due to their increased risk of SLE.

Extranodal hematopoietic neoplasms and mimics in the head and neck: an update

The head and neck region is a common site for extranodal lymphomas, second only to the gastrointestinal tract; and 12% to 15% of all head and neck tumors are lymphomas. Non-Hodgkin lymphomas are most common, and Hodgkin lymphoma occurs rarely at extranodal sites in the head and neck. Most non-Hodgkin lymphomas of the head and neck region are of B-cell lineage, and the Waldeyer ring is the most common site. Head and neck lymphomas have distinctive epidemiological and clinicopathologic features, including an association with immunosuppression, infectious organisms, or autoimmune disorders; site-specific differences (eg, thyroid gland versus ocular adnexa) for common lymphomas, such as extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue; and genetic differences that provide insights into etiology. Furthermore, the diagnosis of non-Hodgkin lymphomas at extranodal sites implies differences in prognosis and therapeutic implications with lymphomas at nodal sites. In this review, we discuss various types of non-Hodgkin lymphomas and Hodgkin lymphoma, focusing on unique aspects related to the head and neck region. We also discuss a number of newer entities that are clinically indolent as well as mimics of lymphoma that can occur in the head and neck region, including infectious mononucleosis, Kikuchi-Fujimoto disease, Kimura disease, Castleman disease, and immunoglobulin G4-related disease.

Imaging findings of variable axillary mass and axillary lymphadenopathy

The axilla is a triangular space that contains mesenchymal tissues such as fat, vessels, nerves and lymph nodes, from which various diseases can develop. This article describes axillary masses and axillary lymphadenopathies using imaging findings from techniques such as ultrasonography, mammography, computed tomography and magnetic resonance imaging. Awareness of the characteristic imaging findings of disease entities that cause axillary masses and various axillary lymphadenopathies will help in the accurate diagnosis of axillary lesions.

Diagnosis of Kikuchi-Fujimoto disease: a comparison between open biopsy and minimally invasive ultrasound-guided core biopsy

Kikuchi-Fujimoto disease (KFD) is a self-limited disease without any need of surgical treatments. Sampling of tissue is the only invasive procedure during the clinical course. However, the standard sampling procedure with accuracy, minimal invasiveness, and esthetic maintenance has not been established yet. In this study, a retrospective review of clinical utility and pathological presentations of the ultrasound-guided core biopsy (USCB) and the open biopsy (OB) in consecutive KFD patients. From 2010 to 2012, 34 consecutive patients were enrolled. USCB was performed in 11 patients, and OB was done in 26 patients. KFD was confirmed in 82% cases by USCB. Similar pathological presentations were found both in the specimens of USCB and OB. In the three patients who had received both USCB and OB, KFD was confirmed by USCB in one case, while two by OB. Sampling errors were found both in USCB and OB. For diagnosing KFD, USCB can serve as the first-line diagnostic tool. OB can be applied only in the failed cases of USCB.

Comparison of clinical features and EBV expression in histiocytic necrotizing lymphadenitis of children and adults

OBJECTIVE

Histiocytic necrotizing lymphadenitis (HNL) is a self-limiting disease characterized by cervical lymphadenopathy and fever. Epstein-Barr virus (EBV) has been implicated as a cause of HNL in some reports but not in others. The aim of this study was to compare the clinical features and laboratory findings in children and adults with HNL and to evaluate the relationship between EBV infection and HNL.

METHODS

The records of patients diagnosed with biopsy-confirmed HNL at Gyeongsang National University Hospital from May 2009 to December 2012 were retrospectively reviewed. Clinical features, laboratory data (blood count, biochemistry, and serology), and computed tomography findings were collected. Immunohistochemistry for CD4, CD8, CD68, and myeloperoxidase (MPO), and in situ hybridization for EBV RNA were performed on archived lymph node biopsies from pediatric and adult patients.

RESULTS

A total of 16 children and 31 adults were diagnosed with HNL. Fever was present in 87.5% of children and 25.8% of adults (P<0.0001). Fever duration was longer for children (mean, 5.06 days) than for adults (mean, 0.63 days; P=0.008). Necrosis of the involved lymph nodes was observed in eight (50%) children and six (19.4%) adults (P=0.045). HNL recurred in five (31.35%) children and one (3.2%) adult (P=0.015). All had detectable CD4, CD8, CD68, and MPO immunoreactivity. EBV reactivity was higher in children (26.7%) than in adults (6.7%) without statistical support.

CONCLUSIONS

There is more variability in the clinical presentation and laboratory findings in children with HNL than in adults. In particular, the degree and duration of fever was more severe in children than in adults, and necrosis of lymph nodes was more frequent in children than in adults. There was no definitive correlation between EBV reactivity and NHL. Further study of the relationship between EBV and HNL is needed with a larger number of patients.

Subacute cutaneous lupus erythematosus onset preceded by Kikuchi-Fujimoto disease

Kikuchi-Fujimoto disease (KFD) is an uncommon clinicopathological entity characterized by fever and lymphadenopathy, predominantly involving cervical lymph nodes, accompanied by chills and leukopenia. The diagnosis relies primarily on the presence of typical morphological features in the swelling lymph nodes. KFD can occur as a benign and self-limiting lymphadenopathy, but it can sporadically precede, postdate or coincide with the diagnosis of systemic lupus erythematosus (SLE). The authors report a case of subacute cutaneous lupus erythematosus (SCLE) in a 42-year-old female preceded by prolonged fever, anemia, leukopenia, and cervical necrotizing lymphadenopathy. About two months later, the patient developed facial and scalp plaques suggestive of lupus skin disease. Histologic and immunologic investigations lead to the diagnosis of SCLE. It is not clear whether KFD associated with lupus skin disease are true KFD or a histopathologic feature of SLE.

Imaging-pathologic correlation of diseases in the axilla

OBJECTIVE

This article reviews the imaging and histopathologic findings of various axillary diseases and suggests management guidelines for radiologists based on imaging findings with clinical correlation.

CONCLUSION

Although axillary diseases may reveal nonspecific imaging findings, a knowledge of the characteristic radiologic manifestations of specific diseases according to anatomic origin (nodal, accessory breast, adipocytic, fibrous, nerve, vascular, stromal, and dermal) and postsurgical lesions aids in establishing an appropriate differential diagnosis and determining whether intervention is necessary.

18F-FDG PET/CT findings in patients with Kikuchi disease

PURPOSE

Kikuchi disease (KD) is a benign and self-limited syndrome characterized by cervical lymphadenopathy. This study evaluated 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) findings in patients with KD and analyzed their imaging features.

PATIENTS, MATERIAL, METHODS

We evaluated the FDG PET/CT findings of 22 patients (14 men, 8 women) with KD, ranging in age from 9 to 73 years. All patients had been diagnosed based on the pathological findings of biopsy. We examined the locations, metabolic activity and size of hypermetabolic lymph nodes (LNs) on FDG PET/CT imaging with medical history including laboratory results.

RESULTS

Among the 22 patients, we identified 619 hypermetabolic LNs which had maximum standard uptake value (SUVmax) above 3.0. The 16 patients were studied with FDG PET/CT to identify the cause of fever, another 5 patients for their neck masses, and the remaining patient for his left inguinal mass. Hypermetabolic LNs were noted in neck (18 bilaterally, 2 right, 1 left) of 21 patients, axilla of 10, mediastinum of 9, abdomen of 17, pelvis of 6, and inguinal area of 3. The SUVmax of FDG uptake in affected LNs by patient base analysis were 6.2-29.4. Of the 619 hypermetabolic LNs identified, 440 LNs (71.1%) were less than 10 mm in their short axis determined by CT, and were occasionally aggregated. No patient showed solid organ hypermetabolic lesion in FDG PET/CT.

CONCLUSION

Kikuchi disease could present multiple hypermetabolic LNs in body on FDG PET/CT. Based on the physical findings, consideration of the generalized distribution of the relatively small-sized hypermetabolic LNs, FDG PET/CT may be useful as a diagnostic tool in cases of Kikuchi disease.

Diagnostic dilemma: Kikuchi's disease or tuberculosis?

Any patient from a tuberculosis (TB) endemic area such as India with classical clinical features of fever, weight loss and lymphadenopathy, making a diagnosis of Kikuchi's disease (KD) prior to waiting for the 6-week culture is not appropriate. KD or histiocytic necrotising lymphadenitis is a rare self-limiting cervical lymphadenitis, often a diagnosis of exclusion. One needs to exclude TB, sarcodosis, lymphoma and autoimmune diseases to make such a diagnosis. The patient here with classical clinical presentation of TB with lymph node biopsy mimicking KD (biopsy and immunohistochemistry) posed a big diagnostic dilemma. However, culture of the biopsied lymphatic tissue was confirmed to be mycobacterium TB after the 6th week of incubation. The patient was treated with antitubercular drugs initially, and later, steroid was added in view of his persistent symptoms and he responded. One should wait for the tissue culture report to confirm or exclude the diagnosis of TB. Exclusion should not be based only on laboratory criteria. Histopathogically, TB can mimic any other granulomatous disorder.

Kikuchi-Fujimoto disease complicated by peripheral neuropathy

Kikuchi-Fujimoto disease is a necrotizing lymphadenitis, mainly characterized by lymphadenopathy, fever, hepatosplenomegaly, nocturnal sweats, myalgia, weight loss, and arthralgia. Its diagnosis is most often based on lymph node biopsy. Differential diagnoses with several other diseases, e.g., malignant lymphoma, necrotizing lymphadenitis, and infective lymphadenopathies, may be challenging. Neurologic involvement is rarely reported in patients diagnosed with Kikuchi-Fujimoto disease. In this subset of patients, the great majority manifest signs involving the central nervous system. We present a 14-year-old boy with a severe form of Kikuchi-Fujimoto disease, complicated by peripheral neuropathy. This patient is interesting for both his age and his peculiar complication.

Kikuchi disease: differentiation from tuberculous lymphadenitis based on patterns of nodal necrosis on CT

BACKGROUND AND PURPOSE

KD, also known as histiocytic necrotizing lymphadenitis, is often mimicked by TL, especially when KD is accompanied by gross necrosis on CT. We analyzed the nodal necrosis patterns on CT in patients with KD and TL to identify the predictive features that differentiate these 2 entities.

MATERIALS AND METHODS

We included 24 patients with KD (14 females, 10 males; mean age, 25.1 years) and 45 with TL (36 women, 9 men; mean age, 39.9 years) having nodal necrosis on CT. The extent, number, location, and margins of nodal necrosis; the presence of perinodal infiltration; and nodal calcification were analyzed. Two attenuation indices for nodal necrosis were derived: CTN and CTN/M. The CT features of the 2 diseases were compared, and multivariate logistic regression analysis was performed to identify predictive features that would aid in differentiating KD from TL.

RESULTS

Mild or moderate extent of nodal necrosis (P = .000), multiple necrotic foci (P = .002), indistinct margins of necrotic foci (P = .000), CTN of >44.5 (P = .000), CTN/M of >0.7 (P = .000), and absence of nodal calcification (P = .012) were associated with KD. Multivariate logistic regression analysis revealed that indistinct margins of necrotic foci were independent predictors, with 80% accuracy.

CONCLUSIONS

The presence of indistinct margins of necrotic foci was an independent predictor in differentiating KD from TL with high diagnostic accuracy.

Histiocytic necrotizing lymphadenitis in the context of systemic lupus erythematosus (SLE): Is histiocytic necrotizing lymphadenitis in SLE associated with skin lesions?

Histiocytic necrotizing lymphadenitis (HNL), or Kikuchi's disease, is a benign and self-limiting lymphadenopathy that typically affects young Asian females. It presents with lymphadenopathy, usually cervical, accompanied by fever, chills and leukopenia. Although the association between systemic lupus erythematosus (SLE) and HNL is rare, the number of reports of HNL in SLE patients is increasing. We present nine cases of HNL in patients with SLE. Among the seven patients with diverse skin manifestations, three had skin manifestations that were histologically compatible with SLE. A review of previous reports in the literature showed that cutaneous involvement was commonly found in HNL in association with SLE. In the patients who had simultaneous onset of both diseases, lupus flare-ups were commonly observed. We suggest that HNL in SLE patients is associated with cutaneous manifestations. This report contributes to our understanding of the relationship between these diseases.

Kikuchi-Fujimoto disease: an amazing response to hydroxychloroquine

Kikuchi-Fujimoto disease is a benign and self-limited disorder. The common clinical features are fever and cervical lymphadenitis. A 9-year-old girl with fever and cervical lymphadenitis was admitted because of persistent symptoms. A cervical lymph node biopsy showed the characteristic features of Kikuchi-Fujimoto disease. Herein, we will discuss the clinical features, diagnosis, and treatment of Kikuchi-Fujimoto disease and highlight the dramatic response when a patient was treated with hydroxychloroquine.

Kikuchi-Fujimoto disease

Kikuchi-Fujimoto disease, or histiocytic necrotizing lymphadenitis, is a self-limited condition, characterized by benign lymphadenopathy with associated fevers and systemic symptoms. It most commonly affects adults younger than 40 years of age and of Asian descent. Involved lymph nodes demonstrate paracortical areas of apoptotic necrosis with abundant karyorrhectic debris and a proliferation of histiocytes, plasmacytoid dendritic cells, and CD8(+) T cells in the absence of neutrophils. Kikuchi-Fujimoto disease is thought to have 3 evolving phases: proliferative, necrotizing, and xanthomatous. The etiology is unknown, although viruses and autoimmune mechanisms have been proposed. No specific laboratory tests contribute to the diagnosis. Diagnosis requires histopathologic examination and exclusion of other factors by ancillary studies. Non-Hodgkin lymphoma and systemic lupus erythematosus should be ruled out before diagnosis of Kikuchi-Fujimoto disease, given the overlapped clinical and histologic features as well as the different therapeutic approaches. Treatment involves supportive measures, and the symptoms usually resolve spontaneously within 4 months.

Kikuchi's disease

Kikuchi disease is an idiopathic, generally self-limiting cause for lymphadenitis that can be clinically and histologically mistaken for lymphoma or systemic lupus erythematosus. Differentiating this disease from common lymphatic disorder is extremely important from the pathologist's point of view, which is highlighted in the article.

Kikuchi-fujimoto disease in a 30-year-old caucasian female

Kikuchi-Fujimoto disease is a rare, self-limited, histiocytic, necrotizing lymphadenitis first described in Japan in 1972. Necrosis of lymph node tissue is caused by apoptosis and may be virally induced. It commonly presents with cervical lymphadenitis and fever. Despite its low incidence, Kikuchi-Fujimoto disease should be considered in patients with persistent lymphadenopathy. Originally thought to occur only in young Asian women, it is now recognized in other geographic regions. We report a 30-year-old white woman with Kikuchi-Fujimoto disease. We discuss the clinical features, differential diagnosis, radiography, pathology, and outcome.

Kikuchi-fujimoto disease: diagnostic dilemma and the role of immunohistochemistry

Kikuchi-Fujimoto (KD) disease is the rare differential diagnoses of chronic cervical lymphadenopathy of unknown etiology. The findings of histopathology may be overlapping, in such condition immunohistochemistry has a definite role to play. Since Tubercular lymphadenopathy is the commonest cause for chronic cervical lymphadenopathy in developing and tropical country like India. Occasionally it is misdiagnosed, ignoring the other rare condition like KD if immunohistochemistry is not taken into consideration to differentiate. As a result the morbidity increases and cost of antitubercular treatment (ATT) in wrong diagnosed case is enormous. We report a similar case of misdiagnoses, non responsive to ATT, finally diagnosed as a case of Kikuchi-Fujimoto disease, did well after recommended treatment.

Sonographic features of axillary lymphadenopathy caused by Kikuchi disease

OBJECTIVE

The purpose of this study was to document the sonographic findings of axillary lymphadenopathy in Kikuchi disease.

METHODS

The medical records and sonographic findings of 7 patients with a pathologic diagnosis of Kikuchi disease in the axillary lymph node by sonographically guided core needle biopsy (n=6) or excisional biopsy (n=1) were reviewed. On sonograms, lymph nodes were assessed for their distribution, size, shape, border, echogenicity, and internal architecture, and those sonographic features of each node were evaluated to determine whether the findings favored malignant or benign lymphadenopathy.

RESULTS

Of the 7 patients (1 man and 6 women; mean age +/- SD, 34.3+/-7.7 years), 29 affected lymph nodes (5-38 mm; mean, 14.8+/-7.2 mm) were identified on sonograms. The sonographic characteristics were as follows: the shortest axis/longest axis ratio of the node (mean, 0.595) was 0.5 or greater in 22 nodes (76%); the border was sharp in 16 (55%); the cortex was hypoechoic in 20 (69%) and isoechoic in 9 (31%); the hilum was narrow in 1 (4%) and absent in 16 (55%); and cortical thickening was found in 13 (45%, concentric in 6 and eccentric in 7). Nineteen lymph nodes (66%) were classified as having malignant-favoring features, and 10 (34%) were classified as having benign-favoring features.

CONCLUSIONS

Many axillary lymph nodes in Kikuchi disease look suspicious sonographically. When lymph nodes in the axilla show suspicious findings on sonograms of relatively young patients, Kikuchi disease can be considered a possible differential diagnosis, and image-guided percutaneous biopsy should be done.

Kikuchi-Fujimoto disease manifesting as recurrent thrombocytopenia and Mobitz type II atrioventricular block in a 7-year-old girl: a case report and analysis of 138 Chinese childhood Kikuchi-Fujimoto cases with 10 years of follow-up in 97 patients

BACKGROUND

The diagnosis of Kikuchi-Fujimoto disease (KFD) is challenging for a paediatrician. Recognizing unusual clinical presentations and features of KFD is essential for doctors to obtain a thorough understanding of this clinical entity.

METHOD

We reported a case recently diagnosed in our ward with manifestation of recurrent thrombocytopenia and Mobitz type II atrioventricular block, which is very unusual in childhood KFD. We also used three powerful Chinese Journal Search Engines (Cqvip.com, Wanfang.data and ScienceChina) to search the cases reported in China from 1989 to 2006.

RESULTS

One hundred seventy-three patients younger than 16 years old with pathologic proof of KFD were identified. Among them, 138 cases with detailed clinical records from eight different provinces and cities were analyzed, and of which 97 patients were followed-up for average of 10 years and the outcomes are discussed.

CONCLUSIONS

KFD is characterized by a spectrum of distinctive features, but also a variety of systemic manifestations. A hyperimmune reaction to unidentified agents as well as an autoimmune component may play an important role in this disease. Early corticosteroid therapy may improve the long-term prognosis of KFD in children.

Haematopathology practice: the commonest problems encountered in a consultation practice

Although not specifically recognized as a subspecialty of histopathology, haematopathology has a long history of specialist practice in the UK, with a few centres attracting large numbers of referred cases. The specialist nature of haematopathology has been enhanced by the advent of immunohistochemistry and, more recently, molecular genetics, which now play a major role in the diagnosis of haematopoietic and lymphoid neoplasms. Problems encountered by non-specialist pathologists, and reflected in those cases submitted for consultation, include difficulties in the differential diagnosis of certain benign lymphoproliferative disorders from lymphoma and the precise classification of lymphomas which may have an impact on therapeutic decisions. Lymphomas that frequently pose problems include common lesions such as follicular lymphoma and more esoteric disorders such as T-cell/histiocyte-rich large B-cell lymphoma. This review is an attempt to clarify a logical approach to the differential diagnosis of these lesions.

Kikuchi's disease displaying a t(2:16) chromosomal translocation

Kikuchi's disease is a rare self-limiting lymphoproliferative condition of unknown aetiology, characterised by acute or subacute necrotising lymphadenitis. It is a benign condition that can mimic malignant lymphoma. In this report, a case of Kikuchi's disease associated with a chromosomal abnormality is described. This is the first report in the literature of such a case and it highlights an important learning point; benign lymphoproliferative conditions can be associated with chromosomal abnormalities that are more typically associated with malignant lymphoproliferative conditions such as malignant lymphoma. The report illustrates the necessity for interpreting cytogenetic data in the relevant clinical and histopathological context in a multidisciplinary setting to avoid misdiagnosis and inappropriate treatment.

[Kikuchi-Fujimoto disease mimicking thyroid metastasis]

INTRODUCTION

Kikuchi-Fujimoto lymphadenopathy is a subacute necrotizing lymphadenopathy of unknown origin. It usually affects cervical lymph nodes. Lymph node biopsy is needed for establishing the diagnosis. This disease must be considered as a possible cause of lymphadenopathy of unknown origin, certainly if classical clinical features lead to diagnostic confusion.

OBSERVATION

A 41-year-old female presented a thyroid cancer treated by thyroidectomy associated with administration of I131. She also presented a right cervical metastasis treated by surgery. She had a cervical right cervical lymphadenopathy, hypermetabolic on the FDG scan, treated by a modified neck dissection. Microscopy of the surgical specimen showed necroziting lymphadenitis.

DISCUSSION

Kikuchi-Fujimoto lymphadenopathy is a subacute necroziting lymphadenopathy of unknown origin, involved more commonly cervical lymph nodes unilaterally. It is more common in Asia, predominantly in young women. This lesion has been reported in patients of virtually any age or gender. No specific biological findings have been described. Lymph node biopsy is needed for establishing the diagnosis. The spontaneous course is usually favorable but one fatal case has been reported.